Search Results (129)

In enzymatic reaction glucose detection chips, the enzyme can easily dislodge from the electrode, which harms both the chip and test stability. Additionally, enzyme activity significantly decreases at low temperatures. Consequently, immobilizing the enzyme at the appropriate substrate and ambient temperature is a critical step for improving the chip. To address this issue, an electrochemical detection chip was modified using the nanomaterial MXene, known for its large specific surface area, excellent adsorption, good dispersion, and high conductivity. Meanwhile, AgNO₃ solution was added to the Ti₃C₂T_x MXene nanosheet solution, and the AgNP@MXene material was prepared by heating in a water bath. This process further enhances photothermal conversion efficiency due to the localized surface plasmon resonance effect of silver nanoparticles and MXene. This MXene-based photothermally enhanced paper chip exhibits outstanding photothermal conversion performance and sensitive photoelectrochemical responsiveness, along with good cycling stability. Moreover, improved glucose detection sensitivity at low winter temperatures has been achieved, and the ambient temperature range of the paper chip has been expanded to 25–37 °C. Full article

Photothermal catalytic CO₂ conversion into chemicals that provide added value represents a promising strategy for sustainable energy utilization, yet the development of highly efficient, stable, and selective catalysts remains a significant challenge. Herein, we report a rationally designed p-n junction heterostructure, T-CZ-PBA (SC), synthesized via controlled pyrolysis of high crystalline Prussian blue analogues (PBA) precursor, which integrates CuCo alloy, ZnO, N-doped carbon (NC), and Zn^II-Co^IIIPBA into a synergistic architecture. This unique configuration offers dual functional advantages: (1) the abundant heterointerfaces provide highly active sites for enhanced CO₂ and H₂ adsorption/activation, and (2) the engineered energy band structure optimizes charge separation and transport efficiency. The optimized T-C₃Z₁-PBA (SC) achieves exceptional photothermal catalytic performance, demonstrating a CO₂ conversion rate of 126.0 mmol gcat⁻¹ h⁻¹ with 98.8% CO selectivity under 350 °C light irradiation, while maintaining robust stability over 50 h of continuous operation. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) investigations have identified COOH* as a critical reaction intermediate and elucidated that photoexcitation accelerates charge carrier dynamics, thereby substantially promoting the conversion of key intermediates (CO₂* and CO*) and overall reaction kinetics. This research provides insights for engineering high-performance heterostructured catalysts by controlling interfacial and electronic structures. Full article

Solar-driven interfacial water evaporation technology coupled with photocatalytic function is regarded as an emerging approach for treating high-salinity organic wastewater, but it remains challenging to design high-performance solar evaporators with excellent photocatalytic properties. Here, we designed a two-dimensional flexible solar interfacial evaporator with photocatalytic function for the purification of high-salinity organic wastewater. The solar evaporator was prepared by the deposition of Cu-based metal organic frameworks (Cu-MOFs) onto a polyester fabric by solvothermal reaction, during which graphitic carbon nitride was also deposited as carried by Cu-MOFs. The solar evaporator achieves an outstanding evaporation rate of 1.95 kg m⁻² h⁻¹ for simulated seawater (3.5 wt% NaCl) under 1 sun. The evaporator also shows efficient evaporation performance and salt resistance for high-concentration saline water due to its outstanding water transport capacity and efficient light absorption ability. Furthermore, salt ions and organic pollutants can be simultaneously removed from high-salinity organic wastewater by the evaporator due to the synergistic effects of adsorption, the photothermal effect and photocatalytic performance. This study successfully integrated photocatalytic technology with solar-driven interfacial evaporation, extending the multifunctionality of solar evaporators for treating high-salinity organic wastewater. Full article

In low-resource and point-of-care settings, traditional PCR often faces challenges of poor sample preparation, adverse environmental conditions, and long assay times. We have previously described a laboratory-based instrument to achieve “adaptive” PCR, a PCR thermocycling control system that replaces preset cycling times and temperatures with the optical monitoring of added L-DNA stereoisomers matching the sequences of the reaction primers and target. These L-DNA biosensors directly monitor DNA hybridization, compensating for ambient environmental conditions and poor sample preparation. This report describes instrument simplifications and a comparative evaluation of both direct photothermal and plasmonic laser heating to reduce the assay time to 15 min. Instrument performance was assessed using a split sample design to compare reaction performances of 1370 and 808 nm adaptive PCR heating modalities to a standard PCR instrument. Both the novel 1370 nm direct heating and the 808 nm plasmonic method achieved target amplification similar to the traditional PCR system within 15 min. However, a major disadvantage of 808 nm heating was nanorod optical interference that reduced the fluorescence signal from PCR probes and optical cycling components. Further characterization of the 1370 nm direct heating method found comparable limits of detection of 10⁰ copies/µL and reaction efficiencies of approximately 2 for both the 1370 nm system and the traditional PCR instrument. These results suggest that a field-deployable PCR instrument design incorporating both adaptive optical control and 1370 nm laser heating can achieve 15 min sample assay times without sacrificing analytical sensitivity. Full article

The enhancement of enzyme activity has garnered significant attention in biotransformation processes and applications. This enhancement is achieved through the use of specific nanomaterials (NMs) with unique physicochemical characteristics responsive to external stimuli. In this study, an enzyme–Fe₃O₄ nano-biocatalytic system (NBS) was developed to enable real-time activation of enzymatic catalysis under alternating magnetic field (AMF) and near-infrared (NIR) irradiation using dual-functional Fe₃O₄ magnetic nanoparticles (MNPs). When exposed to an AMF, Fe₃O₄ MNPs generate molecular vibrations through mechanisms such as Néel or Brown relaxation while acting as a photothermal agent in response to NIR irradiation. The synergistic effect of AMF and NIR irradiation significantly enhanced energy transfer between the enzyme and Fe₃O₄ MNPs, resulting in a maximum 4.3-fold increase in enzyme activity. Furthermore, the system reduced aldol reaction time by 66% (from 4 h to 1.5 h) while achieving 90% product yield. Additionally, factors such as nanoparticle size and NIR power were found to play a critical role in the efficiency of this real-time regulation strategy. The results also demonstrate that the enzyme–Fe₃O₄ nanocomposites (NCs) significantly enhanced catalytic efficiency and reduced the reaction time for aldol reactions. This study demonstrates an efficient NBS controlled via the synergistic effects of AMF and NIR irradiation, enabling spatiotemporal control of biochemical reactions. This work also provides a breakthrough strategy for dynamic biocatalysis, with potential applications in industrial biomanufacturing, on-demand drug synthesis, and precision nanomedicine. Full article

Chemodynamic therapy (CDT), which utilizes the catalytic reactions of nanoparticles to inhibit tumor growth, is a promising approach in cancer therapy. However, its efficacy is limited by insufficient hydrogen peroxide (H₂O₂) concentration in tumor microenvironments and unsatisfactory enzymatic catalytic activity. To overcome these limitations, ultra-small iron-based (USIB) nanoparticles with cascaded superoxide dismutase (SOD)-mimic and peroxidase (POD)-mimic activities have been engineered. USIB nanoparticles initiated by SOD-mimic activity to transform superoxide anions (O₂^·−) into H₂O₂, elevating H₂O₂ levels in the tumor microenvironment and subsequently utilizing POD-mimic activity to convert H₂O₂ into the more reactive ·OH, thereby achieving the destruction of tumor cells. In addition, USIB nanoparticles possess photothermal conversion capabilities, and their enzymatic activity can be significantly enhanced under mild laser irradiation. Therefore, by addressing the issues of insufficient substrate concentration and low enzymatic catalytic activity, the therapeutic efficiency of CDT has been improved. Our research integrates the cascade catalytic reactions of nanozymes with laser irradiation, effectively inhibiting tumor growth and exhibiting outstanding biosafety, demonstrating promising therapeutic potential. Full article

Marble waste is produced on a large scale in many countries, resulting in serious pollution problems. This investigation aimed to study the valorization potential of marble waste from the ornamental rock industry used in the synthesis of a novel calcium niobate–magnesium niobate composite powder prepared by a solid-state reaction between 1000 °C and 1200 °C. The chemical and mineralogical characteristics of the marble waste were determined. Structural and morphological characterizations of the synthesized calcium niobate–magnesium niobate composite powders were conducted by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The thermophysical properties were measured using open photoacoustic cell and photothermal techniques. Structurally, at all synthesis temperatures, the calcium niobate–magnesium niobate powders were found to be composed of a complex mixture of CaNb₂O₆/Ca₂Nb₂O₇/MgNb₂O₆/CaMg_0.33Nb_0.67O₃. In addition, the calcium niobate–magnesium niobate composite powders exhibited low values of thermal diffusivity (1.88–2.15 × 10⁻⁷ m²/s) and thermal conductivity (0.12–0.16 W/mK). The findings of this investigation highlight the potential of marble waste as a promising sustainable source of carbonate for obtaining calcium niobate–magnesium niobate composite powder, which has thermophysical properties that should be explored in low-thermal-conductivity applications. Full article

Photothermal catalytic dry reforming of methane (DRM) technology not only achieves artificial photosynthesis of fuels but also decreases greenhouse effects. The highly efficient photothermal DRM reaction depends on elaborate catalysts. Therefore, unraveling the relationship between property and catalytic efficiency of catalysts is crucial. In this study, a series of Rh-loaded Ga₂O₃-Nb₂O₅ (Rh/Ga_xNb_y) were designed via a simple in situ reduction strategy using Rh₂O₃/Ga₂O₃-Nb₂O₅ as a precursor. After an accurate material characterization, as a proof-of-principle, the photothermal efficiency could be attributed to (i) the amount of medium and strong basic sites on the catalyst surface; (ii) the number of electron–hole pairs upon visible light irradiation. Accordingly, this study used Rh/Ga_xNb_y as a model hybrid catalyst to clarify the relationship between the fundamental properties and photothermal catalytic DRM activities, thus providing guidance for the rational design and fabrication of efficient metal/semiconductor composite catalysts for DRM implementation. Full article

As a carbon-neutral and renewable raw material, cellulose can be transformed into biomass fuels to reduce the dependence on fossil fuels and carbon dioxide emissions. In view of harsh reaction conditions, low selectivity of product, and easy deactivation of the catalyst, this study studied the use of photothermal catalytic technology to convert cellulose into bio-oil rich in levulinic acid. It was discovered that a synergistic effect between heating and photocatalysis is present in cellulose degradation. Different metals were loaded on carbon nanotubes doped with titanium dioxide to prepare different photothermal catalysts, and their catalytic effects on cellulose were compared. It was found that TiO₂-CNT loaded with platinum metal exhibited the highest catalytic performance. By adopting Pt/TiO₂-CNT as the catalyst, the conversion rate of bio-oil reached 99.44%, and the selectivity of LA reached 44.41% at 220 °C for 3 h. As the photothermal catalysis increased the H/C ratio and decreased the O/C ratio of the liquid product, the calorific value reached 21.01 MJ/kg. This study can promote the further industrial application of lignocellulose to prepare fuel oil and decrease the environmental pollution caused by the massive consumption of fossil fuels. Full article

Conventional machines often face limitations due to complex controllers and bulky power supplies, which can hinder their reliability and operability. In contrast, self-excited movements can harness energy from a stable environment for self-regulation. In this study, we present a novel model of a self-rowing boat inspired by paddle boats. This boat is powered by a liquid crystal elastomer (LCE) turntable that acts as a motor and operates under consistent illumination. We investigated the dynamic behavior of the self-rowing boat under uniform illumination by integrating the photothermal reaction theory of LCEs with a nonlinear dynamic framework. The primary equations were solved using the fourth-order Runge–Kutta method. Our findings reveal that the model exhibits two modes of motion under steady illumination: a static pattern and a self-rowing pattern. The transition between these modes is influenced by the interaction of the driving and friction torques generated by photothermal energy. This study quantitatively analyzes the fundamental conditions necessary for initiating a self-rowing motion and examines how various dimensionless parameters affect the speed of the self-rowing system. The proposed system offers several unique advantages, including a simple structure, easy control, and independence from electronic components. Furthermore, it has the potential for miniaturization and integration, enhancing its applicability in miniature machines and systems. Full article

This study meticulously explores two distinct synthesis methods, the solid-state reaction method and the co-precipitation method, for fabricating the spinel-structured solar selective material CuFeMnO₄. By comparing the materials synthesized through these two methods in terms of crystal structure, micro-morphology, particle size distribution, and optical properties, the influence of different preparation methods on the final material performance is revealed. The primary characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy revealed the material’s structural and optical properties, allowing evaluation of the modified synthetic approach’s effectiveness in material design optimization. The results indicate that CuFeMnO₄ prepared by the solid-state method exhibits high crystallinity and good thermal stability under high-temperature conditions. The XRD patterns show that the spinel phase is more prominent and fewer impurities are observed in samples synthesized by the solid-state method. In contrast, the co-precipitation method demonstrates a significant advantage in controlling particle size, with particles of 1–3 μm obtained via the solid-state method and particles of 400–1000 nm synthesized via the co-precipitation method. This study further discusses optimization strategies for both methods, providing theoretical support and a practical basis for the future design and fabrication of efficient solar selective materials. Full article

Liquid organic hydrogen carriers (LOHCs) are recognized as promising sustainable hydrogen (H₂) carriers due to their high volumetric capacity and ability to store H₂ at ambient conditions, eliminating the need for energy-intensive liquefaction or compression processes associated with H₂ or ammonia gas. One of the main current drawbacks, however, is LOHCs’ high energy demand for H₂ release. This work presents the photo-induced liberation of H₂ from formic acid (FA) as a liquid H₂ carrier, using visible light and well-established 5 wt% palladium nanoparticles supported over carbon (Pd/C). We show that low-power light-emitting diodes (LEDs) produced higher gas flow than their thermal baseline (35 $°$C), with 27.2 mL/min and 7.72 mL/min, respectively. Further, the rate of gas evolved with light intensity, catalyst loading, and the concentration of FA. Light-induced dehydrogenation shows similar deactivation as the known thermal mechanisms, such as the decreased Pd²⁺/Pd⁰ ratio and Pd nanoparticle agglomeration. Hence, these observations suggest a photothermal mechanism, whereby the LED provides heat efficiently absorbed by the Pd/C catalyst and enhanced by Pd’s ability to absorb light, thereby driving the FA dehydrogenation reaction at ambient conditions. Full article

Background: Photothermal therapy has the potential to enhance the precision and safety of oncological treatments. However, applicable photothermal agents associated with its photothermal activated immunogenic cell death remain exploiting. Methods: This study evaluates the effectiveness of IR813, a photothermal agent, combined with near-infrared (NIR) light for cancer treatment. In vitro, 4T1 cancer cells were treated with IR813 (5 μg/mL) and exposed to NIR irradiation (1 W/cm²) for 5 min. In vivo, after the tumor-bearing mice administered with IR813 (1 mg/kg) and exposed to NIR irradiation (1 W/cm²) for 10 min, the tumor volume, survival and immune activation were evaluated. Results: IR813 significantly increased the cytotoxicity of 4T1 cancer cells following near-infrared irradiation, resulting in the release of damage-associated molecular patterns and immunogenic cell death. Specifically, the cell viability was reduced to 5% compared to the control group. In vivo, irradiating the accumulation of IR813 at the tumor site had the potential to mediate substantial photothermal tumor suppression, improved mouse survival, and reduced metastasis, with minimal adverse reactions. Furthermore, the immune responses stimulated by IR813-induced photothermal therapy were evidenced by increased mature dendritic cell and cytotoxic T lymphocyte counts and a decrease in regulatory T cells in the spleen, tumor, and lymph nodes. Conclusions: These findings suggest that IR813-induced photothermal therapy is a promising approach for enhancing immunotherapy, directly inhibiting tumors while boosting systemic anti-cancer immunity. Full article

Desalinating seawater is a crucial method for addressing the shortage of freshwater resources. High-efficiency, low-cost, and environmentally friendly desalination technologies are key issues that urgently need to be addressed. This work used Populus tomentosa Carr. as a matrix material and prepared Populus tomentosa Carr.@Fe-GA through a complexation reaction to enhance the water evaporation rate and photothermal conversion efficiency of seawater desalination. The concentration of the impregnation solution was further refined, and the bonding mechanism along with the thermal stability of the composite photothermal material was investigated, including an assessment of their photothermal conversion efficiency. The research results indicate that the evaporation rate of water in a 3.5% NaCl solution for Populus tomentosa Carr.@Fe-GA under light intensity conditions of one sun reached 1.72 kg·m⁻²·h⁻¹, which was an increase of 44.5% compared to untreated Populus tomentosa Carr. It achieved a photothermal conversion efficiency of 95.1%, an improvement of 53.6% over untreated Populus tomentosa Carr., and maintained stability and high evaporation performance (95.4%) even after prolonged rinsing. This work realizes the functional utilization of seawater desalination with Populus tomentosa Carr. and offers a novel approach for the development and use of wood-derived photothermal material. Full article

Photothermal reactions, involving both photochemical and thermal reaction steps, are the most abundant sequences in photochemistry. The derivation of their rate laws is standardized, but the integration of these rate laws has not yet been achieved. Indeed, the field still lacks integrated rate laws for the description of these reactions’ behavior and/or identification of their reaction order. This made difficult a comprehensive account of the photokinetics of photothermal reactions, which created a gap in knowledge. This gap is addressed in the present paper by introducing an unprecedented general model equation capable of mapping out the kinetic traces of such reactions when exposed to light or in the dark. The integrated rate law model equation also applies when the reactive medium is exposed to either monochromatic or polychromatic light irradiation. The validity of the model equation was established against simulated data obtained by a fourth-order Runge–Kutta method. It was then used to describe and quantify several situations of photothermal reactions, such as the effects of initial concentration, spectator molecules, and incident radiation intensity, and the impact of the latter on the photonic yield. The model equation facilitated a general elucidation method to determine the intrinsic reaction parameters (quantum yields and absorptivities of the reactive species) for any photothermal mechanism whose number of species is known. This paper contributes to rationalizing photokinetics along the same general guidelines adopted in chemical kinetics. Full article