Search Results (146)

Electrocatalytic urea synthesis offers great potential for sustainable strategies through CO₂ and NO₃⁻ reduction reactions. However, the development of high-performance catalysts is often hampered by the complexity of synthetic methodologies and the unresolved nature of C-N coupling pathways. In this study, we present a copper–indium co-doped titanium dioxide (CuIn-TiO₂) catalyst that exhibits remarkable efficacy in enhancing the synergistic reduction of CO₂ and NO₃⁻ to produce urea. The bimetallic CuIn site functions as the primary active site for the C-N coupling reaction, achieving a urea yield rate of 411.8 μg h⁻¹ mg_cat⁻¹ with a Faradaic efficiency of 6.7% at −0.8 V versus reversible hydrogen electrode (vs. RHE). A body of experimental and theoretical research has demonstrated that the nanoscale particles enhance the density of active sites and improve the feasibility of reactions on the surface of TiO₂. The co-doping of Cu and In has been shown to significantly enhance electronic conductivity, increase the adsorption affinity for *CO₂ and *NO₃⁻, and promote the C-N coupling process. The CuIn-TiO₂ catalyst has been demonstrated to effectively promote the reduction of NO₃⁻ and CO₂, as well as accelerate the C-N coupling reaction. This effect is a result of a synergistic interaction among the catalyst’s components. Full article

Perylenediimides are an interesting group of compounds that are finding more and more applications. However, the synthetic route of obtaining and modifying them is usually very complicated, costly, and time-consuming. Therefore, the conducted research aimed to develop new, greener, electrochemical methods of obtaining unknown perylenediimides (containing 2-ethylhexyl at the nitrogen atom). For the products obtained in this way, optical and electrochemical studies were conducted and compared with DFT results (i.e., energy gaps and HOMO and LUMO levels). Asa result of optical studies, different emission wavelengths of two isomers originating from the same excitation wavelength were observed. Electrochemical studies also confirmed significant differences in properties between the obtained isomers. Spectroelectrochemical measurements were also performed; they revealed the electrochromic properties of the obtained isomers in the visible and near-infrared range. Considering all the properties (optical and (spectro)electrochemical), the obtained compounds have a high potential for use in optoelectronic devices. Moreover, unprecedented pi-expansion of cis-DBPDI via 1,2-bis(p-bromophenyl)acetylene Diels–Alder cycloaddition into the bay region was also realized successfully. Summing up, electrosynthesis and further pi-expansion via cycloaddition offer a sea of opportunities for obtaining nanographenes. Full article

The growing demand for sustainable bioplastics has driven research toward more efficient and cost-effective methods of producing polyhydroxyalkanoates (PHAs). Among the emerging strategies, bioelectrochemical technologies have been identified as a promising approach to enhance PHA production by supplying electrons to microorganisms either directly or indirectly. This review provides an overview of recent advancements in bioelectrochemical PHA synthesis, highlighting the advantages of this method, including increased production rates, the ability to utilize a wide range of substrates (including industrial and agricultural waste), and the potential for process integration with existing systems. Various bioelectrochemical systems (BES), electrode materials, and microbial strategies used for PHA biosynthesis are discussed, with a focus on the roles of electrode potentials and microbial electron transfer mechanisms in improving the polymer yield. The integration of BES into PHA production processes has been shown to reduce costs, enhance productivity, and support the use of renewable carbon sources. However, challenges remain, such as optimizing reactor design, scaling up processes, and improving the electron transfer efficiency. This review emphasizes the advancement of bioelectrochemical technologies combined with the use of agro-industrial waste as a carbon source, aiming to maximize the efficiency and sustainability of PHA production for large-scale industrial applications. Full article

Electrocatalytic nitrate reduction to ammonia (ENRA) presents a promising strategy for simultaneous environmental remediation and sustainable ammonia synthesis. In this work, a Cu–Co bimetallic catalyst supported on functionalized reduced graphene oxide (RGO) was systematically designed to achieve efficient and selective ammonia production. Surface oxygen functional groups on graphene oxide (GO) were optimized through alkaline hydrothermal treatments, enhancing the anchoring capacity for metal active sites. Characterization indicated the successful formation of uniform Cu–Co bimetallic heterointerfaces comprising metallic and oxide phases, which significantly improved catalyst stability and performance. Among the studied compositions, Cu₆Co₄/RGO exhibited superior catalytic activity, achieving a remarkable ammonia selectivity of 99.86% and a Faradaic efficiency of 96.54% at −0.6 V (vs. RHE). Long-term electrocatalysis demonstrated excellent durability, with over 90% Faradaic efficiency maintained for ammonia production after 20 h of operation. In situ FTIR analysis revealed that introducing Co effectively promoted water dissociation, facilitating hydrogen generation (*H) and accelerating the transformation of nitrate intermediates. This work offers valuable mechanistic insights and paves the way for the design of highly efficient bimetallic electrocatalysts for nitrate reduction and ammonia electrosynthesis. Full article

This work successfully prepared the Co₃O₄ NPs via simple galvanostatic deposition followed by annealing at 400 and 800 °C for two hours. The galvanostatic deposition was carried out from a modified Watts bath. We used Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to examine the oxide’s characterization properties. The nature of the oxide formed was strongly dependent on the annealing temperature. The powder formed at room temperature (25 °C) is a mixture of Co(OH)₂ and metallic Co. However, at 400 and 800 °C, and according to the XRD patterns, the powder consists of the Co₃O₄ phase and a slight quantity of Co(OH)₂ phase. The average particle size measured by TEM ranged from 14.85 nm at room temperature to 90.19 nm at 800 °C. Moreover, the study examined how the operating deposition parameters affected the galvanostatic deposition process. Furthermore, these baths provide NPs, that demonstrate antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria as well as antifungal activity against Aspergillus niger. Full article

Hydrogen peroxide (H₂O₂) is a versatile and environmentally friendly oxidant with broad applications in industry, energy, and environmental remediation. Electrocatalytic H₂O₂ production via the two-electron oxygen reduction reaction (2e⁻ ORR) has emerged as a sustainable alternative to traditional anthraquinone processes. Covalent organic frameworks (COFs), as a class of crystalline porous materials, exhibit high structural tunability, large surface areas, and chemical stability, making them promising electrocatalysts for 2e⁻ ORR. This review systematically summarizes recent advances in COF-based electrocatalysts for H₂O₂ production, including both metal-free and metal-containing systems. We discuss key strategies in COF design—such as dimensional modulation, linkage engineering, heteroatom doping, and post-synthetic modification—and highlight their effects on activity, selectivity, and stability. Fundamental insights into the 2e⁻ ORR mechanism and evaluation metrics are also provided. Finally, we offer perspectives on current challenges and future directions, emphasizing the integration of machine learning, conductivity enhancement, and scalable synthesis to advance COFs toward practical H₂O₂ electrosynthesis. Full article

The electrocatalytic reduction of O₂ via two-electron reaction (2e-ORR) to H₂O₂ represents a promising alternative to the current anthraquinone process, since it is advantageous in the sustainable and decentralized production of H₂O₂. Herein, we report the development of oxygen and nitrogen-rich few-layered graphene-like materials (ms-dcda) by the one-step carbonization of biomass-sourced monosaccharides (D-glucose, D-fructose, D-galactose, D-ribose, D-xylose, L-arabinose, and D-mannose) with the aid of dicyandiamide for electrochemical O₂ reduction to H₂O₂. The ms-dcda materials were porous and possessed wrinkled morphology typical of graphene nanosheets. In H₂O₂ production via 2e-ORR in an acidic electrolyte, these ms-dcda materials were all active and stable catalysts, among which glu-dcda derived from D-glucose and dicyandiamide displayed the lowest onset potential of 0.553 V and the highest selectivity of up to 91.6%. The catalyst was also highly stable in chronoamperometric tests. Selective chemical titration of the C–OH and C=O groups revealed that the latter is far more active and selective than the former in 2e-ORR. Moreover, a positive correlation between the contents of C=O and pyrrolic N and the H₂O₂ partial current suggests that the pyrrolic N group also contributes to 2e-ORR. This work affords a facile strategy for the sustainable fabrication of metal-free carbon-based catalysts efficient for H₂O₂ electrosynthesis. Full article

Electrocatalytic synthesizing of urea through C-N coupling of CO₂ and NO₃⁻ under ambient conditions is a possible solution for the problem of energy consumption in commercial urea production. Herein, we report a Cu-doped CeO₂ catalyst anchored on delaminated MXene two-dimensional surface. The Cu-CeO₂/MXene catalyst achieves the co-reduction of CO₂ and NO₃⁻ to synthesize urea, obtaining a urea yield rate of 505.1 μg·h⁻¹·mg_cat.⁻¹ with a Faradic efficiency (FE) of 6.3% at −0.8 V versus reversible hydrogen electrode (vs. RHE). Theoretical calculations further demonstrate that Cu doping is capable of enhancing the activity of Cu-Ce sites and promoting C-N coupling and protonation reactions. Full article

We studied the influence of different supporting electrolytes (TBAPF₆, TMAPF₆, TEAPF₆, TBAClO₄, and LiClO₄) on the morphology of PEDOT films electrochemically polymerized on screen-printed carbon electrodes, as part of which the synthesis of gold nanoparticles was tested for the subsequent modification of Ki-67 antibodies. Electrochemical deposition of the polymer was carried out using cyclic voltammetry and was characterized in the same way in solutions without the monomer. The nanoparticles were obtained using chronoamperometry at a constant potential for 3 s. The processes of p- and n-doping/undoping of both deposits (with and without gold) were studied, as was their characterization using SEM and ESEM-EDS. It was found that the supporting electrolytes intervened in the morphology and conductivity of the polymer films. In all films, it was possible to electrosynthesize gold nanoparticles, but the type of supporting electrolyte also influenced their distribution, showing that for this study, the most suitable were those obtained using TBAPF6, giving the most promising results for the covalent modification of antibodies to obtain future biosensors. Full article

Spent selective catalytic reduction (SCR) catalysts are hazardous wastes containing many valuable metals whose improper disposal can cause environmental pollution and resource waste. Therefore, it is significant to recover valuable metals from spent SCR catalysts. In this study, the molten salt electrolytic method was employed to treat the SCR catalyst to direct electrosynthesis titanium alloys, which is more environmentally friendly and economical to obtain metal or alloy from secondary resources. A systematic investigation was carried out via experimental analysis and thermodynamic calculation. The results show that high-temperature pretreatment induces the aggregation of W and the formation of CaWO₄. Through molten salt electrolysis, titanium alloys containing Ti(W) and Ti₅Si₃ were formed, with a metal recovery rate of 80–87%. The electrolytic process and the reaction mechanism were also investigated. It is suggested that the molten salt electrolytic method is an effective way to recover valuable metals from spent SCR catalysts. Full article

This paper presents the solar-driven electrocarboxylation of 2-bromopyridine (2-BP) with CO₂ into high-value-added chemicals 2-picolinic acid (2-PA) using dye-sensitized photovoltaics under simulated sunlight. Using three series-connected photovoltaic modules and an Ag electrode with excellent catalytic performance, a Faraday efficiency (FE) of 33.3% is obtained for 2-PA under mild conditions. The experimental results show that photovoltaics-driven systems for electrocarboxylation conversion of CO₂ with heterocyclic halide to afford value-added heterocyclic carboxylic acid are feasible and effective. Full article

Utilizing Rhodopseudomonas palustris (R. pal), this study constructed a dual-chamber microbial electrosynthesis system, based on microbial electrolysis cells, that was capable of producing lycopene. Cultivation within the electrosynthesis chamber yielded a lycopene concentration of 282.3722 mg/L when the optical density (OD) reached 0.6, which was four times greater than that produced by original strains. The mutant strain showed significantly higher levels of extracted riboflavin compared to the wild-type strain, and the riboflavin content of the mutant strain was 61.081 mg/L, which was more than 10 times that of the original strain. Furthermore, sequencing and analyses were performed on the mutant strains observed during the experiment. The results indicated differences in antibiotic resistance genes, carbohydrate metabolism-related genes, and the frequencies of functional genes between the mutant and original strains. The mutant strain displayed potential advantages in specific antibiotic resistance and carbohydrate degradation capabilities, likely attributable to its adaptation to electrogenic growth conditions. Moreover, the mutant strain demonstrated an enrichment of gene frequencies associated with transcriptional regulation, signal transduction, and amino acid metabolism, suggesting a complex genetic adaptation to electrogenic environments. This study presents a novel approach for the efficient and energy-conserving production of lycopene while also providing deeper insights into the genetic basis of electro-resistance genes. Full article

Benzenesulfonamides are an outstandingly important family of compounds in organic and medicinal chemistry. Herein, we report detailed studies on the electrochemical mono- and dideethylation of model compound N,N-diethylbenzenesulfonamide. In this context, all parameters of the electrosynthesis were systematically investigated, with a special emphasis on solvent screening and the effect of water on the outcome of the reaction. Beside a commercially available electrochemical reactor, a custom-made device has also successfully been designed and used in these transformations. Optimization of the reaction led to a green, scaled-up synthesis of the dealkylated products. Our experiments also render the synthesis and potential in situ use of the corresponding N-methoxyalkyl intermediate, a precursor of the reactive and versatile N-sulfonyliminium cation, possible. Full article

Solar-driven CO₂ conversion into high-value-added chemicals, powered by photovoltaics, is a promising technology for alleviating the global energy crisis and achieving carbon neutrality. However, most of these endeavors focus on CO₂ electroreduction to small-molecule fuels such as CO and ethanol. In this paper, inspired by the photosynthesis of green plants and artificial photosynthesis for the electroreduction of CO₂ into value-added fuel, CO₂ artificial photosynthesis for the electrocarboxylation of bromobenzene (BB) with CO₂ to generate the value-added carboxylation product methyl benzoate (MB) is demonstrated. Using two series-connected dye-sensitized photovoltaics and high-performance catalyst Ag electrodes, our artificial photosynthesis system achieves a 61.1% Faraday efficiency (FE) for carboxylation product MB and stability of the whole artificial photosynthesis for up to 4 h. In addition, this work provides a promising approach for the artificial photosynthesis of CO₂ electrocarboxylation into high-value chemicals using renewable energy sources. Full article

Hydrogen peroxide (H₂O₂) is a high-demand chemical, valued as a powerful and eco-friendly oxidant for various industrial applications. The traditional industrial method for producing H₂O₂, known as the anthraquinone process, is both costly and environmentally problematic. Electrochemical synthesis, which produces H₂O₂ using electricity, offers a sustainable alternative, particularly suited for small-scale, continuous on-site H₂O₂ generation due to the portability of electrocatalytic devices. For efficient H₂O₂ electrosynthesis, electrocatalysts must exhibit high selectivity, activity, and stability for the two-electron pathway-oxygen reduction reaction (2e⁻ ORR). Transition-metal chalcogenide (TMC)-based materials have emerged as promising candidates for effective 2e⁻ ORR due to their high activity in acidic environments and the abundance of their constituent elements. This review examines the potential of TMC-based catalysts in H₂O₂ electrosynthesis, categorizing them into noble-metal and non-noble-metal chalcogenides. It underscores the importance of achieving high selectivity, activity, and stability in 2e⁻ ORR. By reviewing recent advancements and identifying key challenges, this review provides valuable insights into the development of TMC-based electrocatalysts for sustainable H₂O₂ production. Full article