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A TiO2 Coated Carbon Aerogel Derived from Bamboo Pulp Fibers for Enhanced Visible Light Photo-Catalytic Degradation of Methylene Blue

State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute at Sichuan University, Chengdu 610065, China
Advanced Polymer Materials Research Center of Sichuan University, Shishi 362700, China
Authors to whom correspondence should be addressed.
Nanomaterials 2021, 11(1), 239;
Submission received: 27 December 2020 / Revised: 4 January 2021 / Accepted: 5 January 2021 / Published: 18 January 2021


Carbon aerogels (CA) derived from bamboo cellulose fibers were coupled with TiO2 to form CA/TiO2 hybrids, which exhibited extraordinary performance on the photo-catalytic degradation of methylene blue (MB). The structure and morphology of CA/TiO2 were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectrum. The CA displayed a highly porous and interconnected three-dimensional framework structure, while introducing the catalytic active sites of TiO2 onto the aerogel scaffold could remarkably enhance its photo-catalytic activity. The adsorption and photo-catalytic degradation of MB by the CA/TiO2 hybrid were investigated. The maximum adsorption capacity of CA/TiO2 for MB was 18.5 mg/g, which outperformed many similar materials reported in the literature. In addition, compared with other photo-catalysts, the present CA/TiO2 demonstrated superior photo-catalytic performance. Almost 85% of MB in 50 mL solution with a MB concentration of 10 mg/L could be effectively degraded by 15 mg CA/TiO2 in 300 min.

1. Introduction

The vast application of dyes in the light industry, especially in textile, leather, paper, plastics, and so on, to obtain colorful products has become a recurring phenomenon. However, residue dyes in effluents raise huge environmental problems which threaten ecosystems, including those on which we as human beings rely. For example, as one of the most frequently used dyes, the discharge of methylene blue (MB) is a major concern due to its adverse impacts on health [1]. Inhaling MB can cause accelerated or difficult breathing. If orally administrated, the affected person may show some strong clinical responses such as burning sensations, mental confusion, vomiting, nausea, and methemoglobinemia [2,3,4]. Hence, the development of eco-friendly and more efficient strategies for the removal of MB in wastewater is of great significance for the aquatic environment.
So far, various methods have been applied to tackle MB pollution in wastewater, such as sonochemical degradation [5], cation exchange [6], electrochemical degradation [7], micellar-enhanced ultrafiltration [8], Fenton-biological treatment [9], and adsorption/precipitation [10]. Among them, photo-catalysis shows promise to settle this problem. As is well known, photo-catalysis can fully degrade organic dyes into small molecules without any secondary pollution and is free from the subsequent separation process [11,12,13]. Titanium dioxide (TiO2) is one of the most popular photo-catalysts, owing to its excellent photo-catalytic performance, low cost, superior stability, and non-toxicity.
Meanwhile, doping with nonmetals (C, N, S) has been proven to be able to produce photo-catalysts with higher efficiencies under visible light [14,15,16,17,18,19]. Specifically, its combination with carbon materials can largely improve the visible light response and photo-catalytic activity [20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]. For example, Esther et al. prepared a carbon xerogel–TiO2 composite through a sol–gel process followed by pyrolysis using resorcinol and formaldehyde as the carbon sources [35]. The micro-morphology analysis indicated that the carbon sphere was coated by TiO2. The interaction between carbon and TiO2, as well as the oxygen vacancies caused by carbonization, could narrow the band gap of TiO2 and consequently improve the visible light response of the composite.
Nonetheless, most photo-catalysts reported previously showed lots of defects and boundaries caused by the aggregation of the carbon matrix. This will inevitably result in the recombination of photo-generated electrons and holes and decrease the photo-catalytic efficiency. Carbon aerogels, a novel species of porous carbon material, have shown promise in various fields [36]. Nonetheless, carbon aerogels are usually derived from synthetic organic compounds. This not only causes fast consumption of the limited non-renewable resources but also brings about secondary pollution to the environment after their service life. Moreover, there are only limited studies focusing on the application of carbon aerogels in photo-catalysis.
Herein, we present a carbon/TiO2 hybrid aerogel (CA/TiO2) using bamboo pulp fibers as the carbon source for the photo-catalytic degradation of MB under visible light. Bamboo is an abundant natural resource in Southwest China. Compared with wood, it only takes several months to grow. In addition, it has a high content of cellulose, with many distinguishing features such as high strength, high flexibility, and low density. Additionally, our previous study suggested that bamboo pulp fibers could be used as a promising precursor material for the preparation of carbon aerogels with ultra-lightweight and high porosity features [37]. Meanwhile, TiO2 was hydrothermally anchored on the surface of fibers and distributed homogeneously along the fibers. The obtained hybrid aerogel was still highly porous with an interconnected three-dimensional framework. This structure could effectively suppress the generation of boundaries and defects and hence decrease the probability of recombination between photo-generated electrons and holes, leading to improved photo-catalytic activity under visible light. In the meantime, the aerogel structure also favored the adsorption of MB as it promoted dye diffusion and provided a higher specific surface area.

2. Materials and Methods

2.1. Materials

The bamboo pulp with a solid content of 25 wt% was supplied by Yongfeng Paper Co., Ltd., Muchuan, China. Tetrabutyl titanate (Ti(OBu)4), acetic acid, and ethanol were of analytical grade and supplied by Kelong Chemical Reagent Co., Ltd., Chengdu, China.

2.2. Synthesis of CA/TiO2

The CA/TiO2 was fabricated by a hydrothermal method using bamboo cellulose and Ti(OBu)4 as the carbon source and titanium dioxide precursor, respectively. In a typical process, bamboo pulp with a determined mass was dispersed in 25 mL deionized water under magnetic stirring to form a homogeneous suspension with a concentration of 1 wt% (solution A). Meanwhile, 1 mL Ti(OBu)4 was added to 5 mL ethanol containing 2.5 mL acetic acid under stirring to form a light yellow solution (solution B). Next, solution B was added into solution A and stirred for 2 h. The mixture was then transferred into a Teflon-lined stainless-steel autoclave and kept at 150 °C for 6 h. After that, the precipitation was centrifuged while it cooled down to room temperature. The obtained powder was re-dispersed into deionized water. Then, the suspension was freeze-dried at −40 °C for 48 h to obtain the cellulose/TiO2 hybrid aerogel.
In order to produce CA/TiO2, the cellulose/TiO2 hybrid aerogel was subjected to high-temperature carbonization in a tube furnace (OTF1200X, Kejing Materials Technology Co., Ltd., Shenzhen, China). The sample was heated to 240 °C at a heating rate of 2 °C/min and kept at this temperature for 1 h. Then, the temperature was increased to 400 °C at a rate of 2 °C/min and kept for 1 h. After that, the temperature was raised to 600 °C at 5 °C/min, followed by an isothermal process for 1 h, and then further heated up to 800 °C at a rate of 5 °C/min and kept for another 2 h. Finally, the sample was cooled down to the ambient temperature naturally. All the pyrolysis processes were conducted in a nitrogen atmosphere. For comparison, a pure carbon aerogel was also prepared in a similar way and denoted as CA.

2.3. Characterization

The micromorphology of CA/TiO2 was observed through field emission scanning electron microscopy (FE-SEM, JEOL JSM-7500F, Tokyo, Japan). The relative contents of the elements were analyzed via energy dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the chemical composition of CA/TiO2. FTIR spectra were acquired from 400 to 4000 cm−1 at a resolution of 4 cm−1 using a FTIR spectrometer (NICOLET 6700, Thermo Fisher Scientific, Waltham, Massachusetts, USA). XPS spectra were recorded on a XPS spectrometer (ESCALAB 250Xi, Thermo Scientific, Waltham, Massachusetts, USA) with an Al Kα X-ray source (1486.8 eV). The crystalline structures were observed through X-ray diffraction (XRD, D8 Advance, Bruker, Karlsruhe, German) using Cu Kα radiation at a wavelength (λ) of 1.541 Å with 2θ angle from 10 to 70°. Raman spectra were obtained on a Raman microspectrometer (STA 6000, Perkin Elmer, Waltham, Massachusetts, USA) with an excitation wavelength of 532 nm. Optical absorption behavior was characterized by a double-beam UV–vis spectrophotometer (UV-3600, Mapada Instruments Co., Shanghai, China) equipped with a Praying Mantis diffuse reflectance accessory (DRS); BaSO4 was used as a reference.

2.4. The Adsorption Performance for MB

A certain amount of CA/TiO2 was immersed into 20 mL solution with the MB concentration varying from 1 to 20 mg/L under dark conditions and shaken for 2 days at ambient temperature. The residual concentration of MB in the solution was calculated by the absorbance of the measured solution according to the standard curve of the MB. When the adsorption equilibrium was reached, the concentration of the remaining MB was evaluated. The concentration of the MB was detected by a UV–vis spectrophotometer at 664 nm. The adsorption capacity of CA/TiO2 for MB was calculated by Equation (1):
q e = V c 0 c e m
where qe (mg/g) is the adsorption capacity for MB, C0 and Ce (mg/L) are the concentrations of MB before and after adsorption, respectively, m (g) is the mass of CA/TiO2, and V (L) is the volume of MB solution.

2.5. Photo-Catalytic Activity Test

The photo-catalytic activity of CA/TiO2 was monitored via the change of MB concentration under the illumination of an ordinary incandescent lamp (200 W, Shuangyi Lighting Electric Appliance Co., Ltd., Shenzhen, China). Firstly, 15 mg CA/TiO2 was added into 50 mL MB solution with a concentration of 10 mg/L for MB adsorption under dark conditions. When the adsorption–desorption process reached equilibrium, the mixture was transferred to the irradiation region of visible light. Equal aliquots of solution were withdrawn from the system every 30 min and measured at 664 nm by a UV–vis spectrophotometer to estimate the concentration of the remaining MB. The photo-catalytic performance was evaluated by the ratio of C/C0, where C is the initial concentration of MB and C0 is the concentration of MB at time t. The experiment was conducted for three times and the average values were presented. In addition, the experimental data of photo-catalytic degradation of MB were fitted to the first-order kinetics model of Equation (2).
ln C t C 0 = k t
where C0, Ct, and k are the initial concentration of MB, the MB concentration at time t, and the rate constant, respectively.

3. Results and Discussion

3.1. Characterization of Materials

Figure 1 shows the morphologies of CA/TiO2 and CA under different magnifications. Some significant differences can be observed. Compared with CA, the fibers in CA/TiO2 exhibited a rougher surface, and their average diameter increased from 7.05 to 8.9 μm. As expected, CA/TiO2 greatly retained the highly porous structure of CA. Figure 1e clearly displays the abundant pores in CA/TiO2. These pores could not only contribute to the adsorption of MB and strengthen the contact between MB and active sites, but also suppress the formation of boundaries and defects from carbon aggregation. Interestingly, the CA/TiO2 had a rather low density (18.5 mg/cm3), which was comparable to and even lower than those of some early reported carbon aerogels derived from biomass [38,39]. Additionally, the EDX results (Figure 1g) indicated that the three elements (C, O, and Ti) existed in the aerogel. Along with the SEM image in Figure 1f, it could be confirmed that TiO2 had been anchored on the carbon fiber scaffold to form a thin layer.
Figure 2 presents the FTIR spectra of CA/TiO2 and CA. The peaks at 2928 cm−1 and 1096 cm−1 are attributed to the C-H and C-O stretching vibrations, respectively. Compared with CA, CA/TiO2 displayed a predominant band at 3441 cm−1, which was assigned to the stretching vibration of surface water and hydroxyl groups on TiO2 [40,41]. It is worth noting that the hydroxyl groups could reduce the recombination possibilities of photo-carriers and generate active oxygen species during the photo-catalytic process [5,40]. Moreover, the new band for CA/TiO2 at 578 cm−1 was ascribed to the vibration of Ti-O-Ti, which consistently suggested that TiO2 had been incorporated in the carbon aerogel.
A Raman spectrum was used to reveal the crystallographic characteristics of CA/TiO2. As shown in Figure 3, the peaks at 1584 and 1336 cm−1 were assigned to the D and G bands, respectively. The D band represents the sp2 units adjacent to structural defects, while the G band corresponds to sp2 planar and conjugated structures [42]. Furthermore, their intensity ratio of IG/ID was employed to depict the order extent of carbon composites. In this study, the calculated IG/ID value of CA/TiO2 was 1.02, smaller than that of CA without TiO2, as reported previously [37]. This implied the increased defects and lattice disorders of carbon in CA/TiO2 [43,44]. The band at 151 cm−1 represented the Eg model of anatase TiO2 [45]. Some early studies revealed that anatase TiO2 has higher photo-catalytic activity, which would benefit the photo-catalytic efficiency of CA/TiO2 [46].
XRD was utilized to analyze the crystalline structures of CA/TiO2. As is well known, TiO2 has two main crystalline phases, anatase and rutile. Because of the high reactivity and chemical stability, most research interest has been focused on the anatase TiO2 [14]. However, anatase is a metastable polymorphic form and will transform to rutile upon heating, which hardly shows any photo-catalytic activity. For pure TiO2, this transformation roughly occurs at 730 °C, while this transition temperature varies according to the specific surface area, the particle size of TiO2, and its purity [47,48]. Furthermore, the presence of carbon phase could also affect the crystal growth of TiO2 in the corresponding composite [49,50]. Figure 4 depicts the XRD pattern of CA/TiO2. The strong peaks at 2θ = 25.5°, 35.3°, 38.0°, 4.1°, 54.1°, 55.1°, and 62.5° could be indexed to the (101), (004), (200), (105), (211), (204), and (215) crystal planes of anatase, respectively. It is interesting to notice that only anatase was observed in the XRD pattern. This seems contradictory to previous reports that when samples were carbonized at 800 °C, only rutile existed in the final products. It was believed that the interaction between the carbon phase and the anatase phase could have avoided the agglomeration and sintering of TiO2 particles and effectively stabilized the anatase phase, preventing the transformation from anatase to rutile, even at a high temperature [35].
XPS (Figure 5a) was used to analyze the surface chemical composition of CA/TiO2. According to the literature, pure TiO2 presents only one peak of Ti4+, located at the binding energy BE = 459.1 eV in a deconvoluted Ti2p spectrum [51]. However, the deconvoluted Ti2p spectrum of CA/TiO2 (Figure 5b) displayed two components at 459.1 and 458.0 eV, respectively. The first peak corresponded to the Ti4+, while the other peak at 458.0 eV was attributed to the Ti3+ [52], suggesting that there was a reduction reaction of organic phase during carbonization [35,52].
In the XPS spectrum of O1s (Figure 5c), four peaks located at BE = 529.9, 531.6, 532.9, and 533.8 eV could be observed. As previously reported, the component at BE = 530.2 eV was assigned to the oxygen bonded to Ti4+, and the peak at BE = 531.3 eV corresponded to the oxygen bonded to Ti3+ [48]. The two components at 532.9 and 533.6 eV were attributed to the oxygenated surface groups of the carbon phase, like C=O and C-O. Notably, these oxygen-containing groups not only favored the dispersing and anchoring of TiO2 on the carbon scaffold, but also substituted for the lattice oxygen and formed Ti-O-C bonds, giving rise to carbon doping [53,54,55,56].

3.2. Optical Property

Due to the intrinsic band gap, TiO2 could only absorb ultraviolet light. Figure 6 shows the diffuse reflectance UV–vis spectrum of CA/TiO2, which displayed a strong absorption in the visible light wavelength range of 400–800 nm. This result can be attributed to the following reasons. On the one hand, the quantum confinement by the well-dispersed TiO2 on the carbon scaffold and the carbon-doping as a result of the formation of Ti-O-C could remarkably narrow the band gap of TiO2 [54,57]. On the other hand, the oxygen vacancies generated during carbonization and the partially reduced Ti4+ as confirmed by XPS might have acted as a new state in between the band gap of TiO2, leading to the intense visible light absorption. This agrees well with a recent study on CNT/TiO2 for water splitting [58].

3.3. Adsorption and Photo-Catalytic Activity Study

Figure 7 displays the MB adsorption curve of CA/TiO2. The adsorption capacity of CA/TiO2 for MB increased with the increase of MB concentration in the solution. Additionally, the maximum adsorption capacity was 18.5 mg/g, higher than those of many other similar materials. For example, Zhang [59] et al. prepared a TiO2/carbon@TiO2 composite with a core–shell structure; its adsorption capacity was 11.4 mg/g. Wang [54] prepared a TiO2/carbon composite using cotton as the carbon source, which exhibited an adsorption capacity of 8 mg/g.
The improved adsorption capacity of CA/TiO2 should be ascribed to the large amount of hydroxyl groups presented in CA/TiO2, which had a preferable affinity with the positively charged MB molecule. Additionally, the abundant interconnected pores favored the diffusing process of MB from the solution into the material. As a consequence, more MB molecules could be attracted around TiO2, giving rise to improved photo-catalytic efficiency.
The photo-catalytic activity of CA/TiO2 was evaluated by monitoring the degradation of MB under a common incandescent lamp. Because the aerogel materials also had a strong adsorption towards MB, all samples were saturated with MB under dark conditions prior to the testing of photo-catalytic activity. Figure 8 compares the photo-catalytic performance of CA/TiO2 and CA. As expected, CA exhibited no photo-catalytic activity. By contrast, CA/TiO2 could efficiently degrade MB. Using only 15 mg of CA/TiO2, nearly 85% of MB in 50 mL solution with a concentration of 10 mg/L was degraded in 300 min, and the initial solution in blue was almost completely decolored after photo-degradation (see the inset image in Figure 8). In addition, the first-order degradation kinetics plot of MB by CA/TiO2 was analyzed and is shown in Figure 9 [54]. The plot appeared to have good linearity with a high correlation coefficient (R2 = 0.9828) and a k value of 0.0039 min−1. It is noteworthy that the photo-catalytic efficiency of CA/TiO2 was higher than those of many other similar photo-catalysts in the literature. For example, Esther [35] et al. prepared a carbon xerogel–TiO2 composite, and 800 mg of the photo-catalyst removed 90% of dye (800 mL, 10 mg/L) in 400 min. Wang [54] et al. used a TiO2–carbon fiber composite as the photo-catalyst to degrade MB under visible light. The results indicated that 120 mg composite could degrade 80% of the dye in 100 mL MB solution (10 mg/L) after 10 h. Chen [60] et al. synthesized a TiO2/carbon photo-catalyst to degrade MB under visible light, and 125 mg of the photo-catalyst degraded 90% MB in 250 mL solution (5 mg/L) after 7 h.
The superior photo-catalytic activity of CA/TiO2 could be explained by the following facts. The catalytic active site of TiO2 was anchored on the surface of carbon fiber to form a thin layer. This structure could reduce the distance that the photo-generated electrons and holes need to travel and decrease the recombination probability between these electrons and holes. Additionally, CA/TiO2 had a highly porous and interconnected three-dimensional framework structure, which could effectively prohibit the generation of boundaries and defects (which often lead to the recombination of photo-generated electron–hole pairs) due to carbon aggregation. Last but not least, the high adsorption capacity of CA/TiO2 resulted in the enrichment of MB around TiO2, which improved the contact between MB and the photo-catalyst and ultimately enhanced the photo-catalytic efficiency.

4. Conclusions

In this work, CA/TiO2 was synthesized via hydrothermal and carbonization processes using bamboo pulp fibers and Ti(OBu)4 as the raw materials. An instrumental analysis indicated that the catalytic active site of TiO2 was well dispersed and homogeneously anchored on the surface of carbon fibers. The obtained TiO2 had a crystalline structure indexed to anatase. This was resultant from the interaction between carbon and TiO2, which prevented the transformation from anatase to rutile during the high-temperature carbonization process. The obtained CA/TiO2 was highly porous and exhibited outstanding adsorption and photo-catalytic properties for MB decolorization. It is envisaged that the high-performance CA/TiO2 photo-catalyst from low-cost and sustainable bioresources may find great potential in treating organic dye polluted wastewaters.

Author Contributions

Conceptualization, J.Z. (Jian Zhang) and W.Y.; data curation, Q.W.; formal analysis, J.Z. (Jian Zhang), W.Y., and C.A.; funding acquisition, W.Z. and C.L.; investigation, J.Z. (Jiangqi Zhao); methodology, J.Z. (Jian Zhang) and W.Y.; project administration, W.Z. and C.L.; resources, B.H.; software, J.Z. (Jian Zhang) and T.X.; supervision, C.L.; validation, J.Z. (Jian Zhang), W.Y., and W.Z.; visualization, J.Z. (Jian Zhang); writing—original draft, J.Z. (Jian Zhang) and W.Y.; writing—review and editing, W.Z. All authors have read and agreed to the published version of the manuscript.


This research was funded by the National Natural Science Foundation of China (51861165203), the Sichuan Science and Technology Program (2019YJ0125), the State Key Laboratory of Polymer Materials Engineering (sklpme2019-2-19), the Opening Project of Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization (HZXYKFKT201902), and the Special Foundation for Innovation-Driven Development of Hezhou (Hekechuang PT0710004).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available within this article. Further inquiries may be directed to the authors.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Rafatullah, M.; Sulaiman, O.; Hashim, R.; Ahmad, A. Adsorption of methylene blue on low-cost adsorbents: A review. J. Hazard. Mater. 2010, 177, 70–80. [Google Scholar] [CrossRef] [PubMed]
  2. Ghosh, D.; Bhattacharyya, K.G. Adsorption of methylene blue on kaolinite. Appl. Clay Sci. 2002, 20, 295–300. [Google Scholar] [CrossRef]
  3. Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H. Adsorption of basic dye on high-surface-area activated carbon prepared from coconut husk: Equilibrium, kinetic and thermodynamic studies. J. Hazard. Mater. 2008, 154, 337–346. [Google Scholar] [CrossRef] [PubMed]
  4. Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H. Adsorption of basic dye using activated carbon prepared from oil palm shell: Batch and fixed bed studies. Desalination 2008, 225, 13–28. [Google Scholar] [CrossRef]
  5. Abbasi, M.; Asl, N.R. Sonochemical degradation of Basic Blue 41 dye assisted by nanoTiO2 and H2O2. J. Hazard. Mater. 2008, 153, 942–947. [Google Scholar] [CrossRef] [PubMed]
  6. Wu, J.-S.; Liu, C.-H.; Chu, K.H.; Suen, S.-Y. Removal of cationic dye methyl violet 2B from water by cation exchange membranes. J. Membr. Sci. 2008, 309, 239–245. [Google Scholar] [CrossRef]
  7. Fan, L.; Zhou, Y.; Yang, W.; Chen, G.; Yang, F. Electrochemical degradation of aqueous solution of Amaranth azo dye on ACF under potentiostatic model. Dye. Pigment. 2008, 76, 440–446. [Google Scholar] [CrossRef]
  8. Zaghbani, N.; Hafiane, A.; Dhahbi, M. Removal of Safranin T from wastewater using micellar enhanced ultrafiltration. Desalination 2008, 222, 348–356. [Google Scholar] [CrossRef]
  9. Lodha, B.; Chaudhari, S. Optimization of Fenton-biological treatment scheme for the treatment of aqueous dye solutions. J. Hazard. Mater. 2007, 148, 459–466. [Google Scholar] [CrossRef]
  10. Zhu, M.-X.; Lee, L.; Wang, H.-H.; Wang, Z. Removal of an anionic dye by adsorption/precipitation processes using alkaline white mud. J. Hazard. Mater. 2007, 149, 735–741. [Google Scholar] [CrossRef]
  11. Lin, Y.; Li, D.; Hu, J.; Xiao, G.; Wang, J.; Li, W.; Fu, X. Highly Efficient Photocatalytic Degradation of Organic Pollutants by PANI-Modified TiO2 Composite. J. Phys. Chem. C 2012, 116, 5764–5772. [Google Scholar] [CrossRef]
  12. Huang, Y.; Ho, S.; Lu, Y.; Niu, R.; Xu, L.; Cao, J.; Lee, S. Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect. Molecules 2016, 21, 56. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  13. Herney-Ramirez, J.; Vicente, M.A.; Madeira, L.M. Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: A review. Appl. Catal. B Environ. 2010, 98, 10–26. [Google Scholar] [CrossRef]
  14. Asahi, R.; Morikawa, T.; Irie, H.; Ohwaki, T. Nitrogen-Doped Titanium Dioxide as Visible-Light-Sensitive Photocatalyst: Designs, Developments, and Prospects. Chem. Rev. 2014, 114, 9824–9852. [Google Scholar] [CrossRef]
  15. Asahi, R.; Morikawa, T.; Ohwaki, T.; Aoki, K.; Taga, Y. Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides. Science 2001, 293, 269–271. [Google Scholar] [CrossRef]
  16. Han, C.; Pelaez, M.; Likodimos, V.; Kontos, A.G.; Falaras, P.; O’Shea, K.; Dionysiou, D.D. Innovative visible light-activated sulfur doped TiO2 films for water treatment. Appl. Catal. B Environ. 2011, 107, 77–87. [Google Scholar] [CrossRef]
  17. Dong, F.; Guo, S.; Wang, H.; Li, X.; Wu, Z. Enhancement of the Visible Light Photocatalytic Activity of C-Doped TiO2 Nanomaterials Prepared by a Green Synthetic Approach. J. Phys. Chem. C 2011, 115, 13285–13292. [Google Scholar] [CrossRef]
  18. Su, W.; Zhang, Y.; Li, Z.; Wu, L.; Wang, X.; Li, J.; Fu, X. Multivalency Iodine Doped TiO2:  Preparation, Characterization, Theoretical Studies, and Visible-Light Photocatalysis. Langmuir 2008, 24, 3422–3428. [Google Scholar] [CrossRef]
  19. Yu, J.C.; Yu, J.G.; Ho, W.; Jiang, Z.T.; Zhang, L.Z. Effects of F- Doping on the Photo-catalytic Activity and Microstructures of Nanocrystalline TiO2 Powders. Chem. Mater. 2002, 14, 3808–3816. [Google Scholar] [CrossRef]
  20. Qi, D.; Xing, M.; Zhang, J. Hydrophobic Carbon-Doped TiO2/MCF-F Composite as a High Performance Photocatalyst. J. Phys. Chem. C 2014, 118, 7329–7336. [Google Scholar] [CrossRef]
  21. Huang, J.F.; Liu, J.M.; Xiao, L.M. Facile synthesis of porous hybrid materials based on Calix-3 dye and TiO2 for high photocatalytic water splitting performance with excellent stability. J. Mater. Chem. A 2019, 7, 2993–2999. [Google Scholar] [CrossRef]
  22. Jiang, Z.; Zhu, C.; Wan, W.; Qian, K.; Xie, J. Constructing graphite-like carbon nitride modified hierarchical yolk-shell TiO2 spheres for water pollution treatment and hydrogen production. J. Mater. Chem. A 2016, 4, 1806–1818. [Google Scholar] [CrossRef]
  23. Zhang, Y.; Tang, Z.-R.; Fu, X.; Xu, Y.-J. Engineering the Unique 2D Mat of Graphene to Achieve Graphene-TiO2 Nanocomposite for Photocatalytic Selective Transformation: What Advantage does Graphene Have over Its Forebear Carbon Nanotube? ACS Nano 2011, 5, 7426–7435. [Google Scholar] [CrossRef] [PubMed]
  24. Cho, K.M.; Kim, K.H.; Choi, H.O.; Jung, H.-T. A highly photoactive, visible-light-driven graphene/2D mesoporous TiO2 photocatalyst. Green Chem. 2015, 17, 3972–3978. [Google Scholar] [CrossRef]
  25. Xing, M.; Li, X.; Zhang, J. Synergistic effect on the visible light activity of Ti3+ doped TiO2 nanorods/boron doped graphene composite. Sci. Rep. 2014, 4, 5493. [Google Scholar] [CrossRef] [PubMed]
  26. Tan, L.-L.; Ong, W.-J.; Chai, S.-P.; Mohamed, A.R. Reduced graphene oxide-TiO2 nanocomposite as a promising visible-light-active photocatalyst for the conversion of carbon dioxide. Nanoscale Res. Lett. 2013, 8, 465. [Google Scholar] [CrossRef] [Green Version]
  27. Cai, X.; Li, J.; Liu, Y. Titanium dioxide-coated biochar composites as adsorptive and photocatalytic degradation materials for the removal of aqueous organic pollutants. Chem. Technol. Biotechnol. 2018, 93, 783–791. [Google Scholar] [CrossRef]
  28. Lee, W.J.; Lee, J.M.; Kochuveedu, S.T.; Han, T.H.; Jeong, H.Y.; Park, M.; Yun, J.M.; Kwon, J.; No, K.; Kim, D.H.; et al. Biomineralized N-Doped CNT/TiO2 Core/Shell Nanowires for Visible Light Photocatalysis. ACS Nano 2012, 6, 935–943. [Google Scholar] [CrossRef]
  29. Reddy, K.R.; Hassan, M.; Gomes, V.G. Hybrid nanostructures based on titanium dioxide for enhanced photocatalysis. Appl. Catal. A Gen. 2015, 489, 1–16. [Google Scholar] [CrossRef]
  30. Zhao, L.; Chen, X.; Wang, X.; Zhang, Y.; Wei, W.; Sun, Y.; Antonietti, M.; Titirici, M.M. One-Step Solvothermal Synthesis of a Carbon@TiO2 Dyade Structure Effectively Promoting Visible-Light Photocatalysis. Adv. Mater. 2010, 22, 3317–3321. [Google Scholar] [CrossRef]
  31. Zhuang, J.; Tian, Q.; Zhou, H.; Liu, Q.; Liu, P.; Zhong, H. Hierarchical porous TiO2@C hollow microspheres: One-pot synthesis and enhanced visible-light photocatalysis. J. Mater. Chem. 2012, 22, 7036–7042. [Google Scholar] [CrossRef]
  32. Zhao, D.; Sheng, G.; Chen, C.; Wang, X. Enhanced photocatalytic degradation of methylene blue under visible irradiation on graphene@TiO2 dyade structure. Appl. Catal. B Environ. 2012, 111–112, 303–308. [Google Scholar] [CrossRef]
  33. Tan, L.-L.; Ong, W.-J.; Chai, S.-P.; Goh, B.T.; Mohamed, A.R. Visible-light-active oxygen-rich TiO2 decorated 2D graphene oxide with enhanced photocatalytic activity toward carbon dioxide reduction. Appl. Catal. B Environ. 2015, 179, 160–170. [Google Scholar] [CrossRef]
  34. Li, X.; Jiang, Y.; Cheng, W.; Li, Y.; Xu, X.; Lin, K. Mesoporous TiO2/Carbon Beads: One-Pot Preparation and Their Application in Visible-Light-Induced Photodegradation. Nano-Micro Lett. 2015, 7, 243–254. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  35. Bailón-García, E.; Elmouwahidi, A.; Álvarez, M.A.; Carrasco-Marín, F.; Pérez-Cadenas, A.F.; Maldonado-Hódar, F.J. New carbon xerogel-TiO2 composites with high performance as visible-light photocatalysts for dye mineralization. Appl. Catal. B Environ. 2017, 201, 29–40. [Google Scholar] [CrossRef]
  36. Moreno-Castilla, C.; Maldonado-Hódar, F.J. Carbon aerogels for catalysis applications: An overview. Carbon 2005, 43, 455–465. [Google Scholar] [CrossRef]
  37. Yuan, W.; Zhang, X.; Zhao, J.; Li, Q.; Ao, C.; Xia, T.; Zhang, W.; Lu, C. Ultra-lightweight and highly porous carbon aerogels from bamboo pulp fibers as an effective sorbent for water treatment. Results Phys. 2017, 7, 2919–2924. [Google Scholar] [CrossRef]
  38. Li, Y.-Q.; Samad, Y.A.; Polychronopoulou, K.; Alhassan, S.M.; Liao, K. Carbon Aerogel from Winter Melon for Highly Efficient and Recyclable Oils and Organic Solvents Absorption. ACS Sustain. Chem. Eng. 2014, 2, 1492–1497. [Google Scholar] [CrossRef]
  39. Han, S.; Sun, Q.; Zheng, H.; Li, J.; Jin, C. Green and facile fabrication of carbon aerogels from cellulose-based waste newspaper for solving organic pollution. Carbohydr. Polym. 2016, 136, 95–100. [Google Scholar] [CrossRef]
  40. He, D.; Li, Y.; Wang, I.; Wu, J.; Yang, Y.; An, Q. Carbon wrapped and doped TiO2 mesoporous nanostructure with efficient visible-light photocatalysis for NO removal. Appl. Surf. Sci. 2017, 391, 318–325. [Google Scholar] [CrossRef]
  41. Kataoka, S.; Tejedor-Tejedor, M.I.; Coronado, J.M.; Anderson, M.A. Thin-film transmission IR spectroscopy as an in situ probe of the gas–solid interface in photocatalytic processes. J. Photochem. Photobiol. A Chem. 2004, 163, 323–329. [Google Scholar] [CrossRef]
  42. Sang, Y.; Zhao, Z.; Tian, J.; Hao, P.; Jiang, H.; Liu, H.; Claverie, J.P. Enhanced Photocatalytic Property of Reduced Graphene Oxide/TiO2 Nanobelt Surface Heterostructures Constructed by an In Situ Photochemical Reduction Method. Small 2014, 10, 3775–3782. [Google Scholar] [CrossRef] [PubMed]
  43. Yu, X.; Liu, J.; Yu, Y.; Zuo, S.; Li, B. Preparation and visible light photocatalytic activity of carbon quantum dots/TiO2 nanosheet composites. Carbon 2014, 68, 718–724. [Google Scholar] [CrossRef]
  44. Guo, S.; Zhang, G.; Guo, Y.; Yu, J.C. Graphene oxide–Fe2O3 hybrid material as highly efficient heterogeneous catalyst for degradation of organic contaminants. Carbon 2013, 60, 437–444. [Google Scholar] [CrossRef]
  45. Marie, J.; Berthon-Fabry, S.; Chatenet, M.; Chainet, E.; Pirard, R.; Cornet, N.; Achard, P. Platinum supported on resorcinol–formaldehyde based carbon aerogels for PEMFC electrodes: Influence of the carbon support on electrocatalytic properties. J. Appl. Electrochem. 2007, 37, 147–153. [Google Scholar] [CrossRef]
  46. Wiener, M.; Reichenauer, G.; Braxmeier, S.; Hemberger, F.; Ebert, H.-P. Carbon Aerogel-Based High-Temperature Thermal Insulation. Int. J. Thermophys. 2009, 30, 1372–1385. [Google Scholar] [CrossRef]
  47. Bock, V.; Nilsson, O.; Blumm, J.; Fricke, J. Thermal properties of carbon aerogels. J. Non-Cryst. Solids 1995, 185, 233–239. [Google Scholar] [CrossRef]
  48. Hanaor, D.A.H.; Sorrell, C.C. Review of the anatase to rutile phase transformation. J. Mater. Sci. 2011, 46, 855–874. [Google Scholar] [CrossRef] [Green Version]
  49. Maldonado-Hódar, F.J.; Moreno-Castilla, C.; Rivera-Utrilla, J. Synthesis, pore texture and surface acid–base character of TiO2/carbon composite xerogels and aerogels and their carbonized derivatives. Appl. Catal. A Gen. 2000, 203, 151–159. [Google Scholar] [CrossRef]
  50. Moreno-Castilla, C.; Maldonado-Hodar, F.J. Synthesis and surface characteristics of silica- and alumina-carbon composite xerogels. Phys. Chem. Chem. Phys. 2000, 2, 4818–4822. [Google Scholar] [CrossRef]
  51. Gonzalez-Elipe, A.R.; Malet, P.; Espinos, J.P.; Caballero, A.; Munuera, G. Effect of Water in the Encapsulation of the Metallic Phase During Smsi Generation in Pt/TiO2 Catalysts. Struct. React. Surf. 1989, 48, 427–436. [Google Scholar] [CrossRef]
  52. González-Elipe, A.R.; Fernández, A.; Espinós, J.P.; Munuera, G. Role of hydrogen in the mobility of phases in Ni TiOx systems. J. Catal. 1991, 131, 51–59. [Google Scholar] [CrossRef]
  53. Pastrana-Martínez, L.M.; Morales-Torres, S.; Likodimos, V.; Falaras, P.; Figueiredo, J.L.; Faria, J.L.; Silva, A.M.T. Role of oxygen functionalities on the synthesis of photocatalytically active graphene–TiO2 composites. Appl. Catal. B Environ. 2014, 158–159, 329–340. [Google Scholar] [CrossRef]
  54. Wang, B.; Karthikeyan, R.; Lu, X.-Y.; Xuan, J.; Leung, M.K.H. High photocatalytic activity of immobilized TiO2 nanorods on carbonized cotton fibers. J. Hazard. Mater. 2013, 263, 659–669. [Google Scholar] [CrossRef] [PubMed]
  55. Wang, H.; Wu, Z.; Liu, Y. A Simple Two-Step Template Approach for Preparing Carbon-Doped Mesoporous TiO2 Hollow Microspheres. J. Phys. Chem. C 2009, 113, 13317–13324. [Google Scholar] [CrossRef]
  56. Zhang, Y.; Zhao, Z.; Chen, J.; Cheng, L.; Chang, J.; Sheng, W.; Hu, C.; Cao, S. C-doped hollow TiO2 spheres: In situ synthesis, controlled shell thickness, and superior visible-light photocatalytic activity. Appl. Catal. B Environ. 2015, 165, 715–722. [Google Scholar] [CrossRef]
  57. Monticone, S.; Tufeu, R.; Kanaev, A.V.; Scolan, E.; Sanchez, C. Quantum size effect in TiO2 nanoparticles: Does it exist? Appl. Surf. Sci. 2000, 162–163, 565–570. [Google Scholar] [CrossRef]
  58. Moya, A.; Cherevan, A.; Marchesan, S.; Gebhardt, P.; Prato, M.; Eder, D.; Vilatela, J.J. Oxygen vacancies and interfaces enhancing photocatalytic hydrogen production in mesoporous CNT/TiO2 hybrids. Appl. Catal. B Environ. 2015, 179, 574–582. [Google Scholar] [CrossRef] [Green Version]
  59. Zhang, G.; Teng, F.; Zhao, C.; Chen, L.; Zhang, P.; Wang, Y.; Gong, C.; Zhang, Z.; Xie, E. Enhanced photocatalytic activity of TiO2/carbon@TiO2 core–shell nanocomposite prepared by two-step hydrothermal method. Appl. Surf. Sci. 2014, 311, 384–390. [Google Scholar] [CrossRef]
  60. Chen, D.; Jiang, Z.; Geng, J.; Wang, A.Q.; Yang, D. Carbon and Nitrogen Co-doped TiO2 with Enhanced Visible-Light Photocatalytic Activity. Huazhong Norm. Univ. J. Postgrad. 2010, 46, 2741–2746. [Google Scholar] [CrossRef]
Figure 1. SEM images of carbon aerogels (CA) (ac) and CA/TiO2 (df) and energy dispersive X-ray spectroscopy (EDX) results for CA/TiO2 (g).
Figure 1. SEM images of carbon aerogels (CA) (ac) and CA/TiO2 (df) and energy dispersive X-ray spectroscopy (EDX) results for CA/TiO2 (g).
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Figure 2. FTIR spectra of CA and CA/TiO2.
Figure 2. FTIR spectra of CA and CA/TiO2.
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Figure 3. Raman spectrum of CA/TiO2.
Figure 3. Raman spectrum of CA/TiO2.
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Figure 4. XRD pattern of CA/TiO2.
Figure 4. XRD pattern of CA/TiO2.
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Figure 5. XPS spectrum (a) and deconvoluted Ti2p spectrum (b) and O1s spectrum (c) of CA/TiO2.
Figure 5. XPS spectrum (a) and deconvoluted Ti2p spectrum (b) and O1s spectrum (c) of CA/TiO2.
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Figure 6. Diffuse reflectance spectrum of CA/TiO2.
Figure 6. Diffuse reflectance spectrum of CA/TiO2.
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Figure 7. Adsorption isotherm of methylene blue (MB).
Figure 7. Adsorption isotherm of methylene blue (MB).
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Figure 8. Photo-catalytic degradation of MB by CA/TiO2 and CA. The insert shows the color change of the solution before and after the CA/TiO2 treatment.
Figure 8. Photo-catalytic degradation of MB by CA/TiO2 and CA. The insert shows the color change of the solution before and after the CA/TiO2 treatment.
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Figure 9. First-order degradation kinetics plot of MB by CA/TiO2.
Figure 9. First-order degradation kinetics plot of MB by CA/TiO2.
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Zhang, J.; Yuan, W.; Xia, T.; Ao, C.; Zhao, J.; Huang, B.; Wang, Q.; Zhang, W.; Lu, C. A TiO2 Coated Carbon Aerogel Derived from Bamboo Pulp Fibers for Enhanced Visible Light Photo-Catalytic Degradation of Methylene Blue. Nanomaterials 2021, 11, 239.

AMA Style

Zhang J, Yuan W, Xia T, Ao C, Zhao J, Huang B, Wang Q, Zhang W, Lu C. A TiO2 Coated Carbon Aerogel Derived from Bamboo Pulp Fibers for Enhanced Visible Light Photo-Catalytic Degradation of Methylene Blue. Nanomaterials. 2021; 11(1):239.

Chicago/Turabian Style

Zhang, Jian, Wei Yuan, Tian Xia, Chenghong Ao, Jiangqi Zhao, Bingxue Huang, Qunhao Wang, Wei Zhang, and Canhui Lu. 2021. "A TiO2 Coated Carbon Aerogel Derived from Bamboo Pulp Fibers for Enhanced Visible Light Photo-Catalytic Degradation of Methylene Blue" Nanomaterials 11, no. 1: 239.

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