Simulated Solar Irradiation Research Articles

Synthesis, Characterization, and Photocatalytic Properties of Sol-Gel Ce-TiO2 Films

In this study, nanostructured cerium-doped TiO2 (Ce-TiO2) films with the addition of different amounts of cerium (0.00, 0.08, 0.40, 0.80, 2.40, and 4.10 wt.%) were deposited on a borosilicate glass substrate by the flow coating sol-gel process. After flow coating, the deposited films were dried at a temperature of 100 °C for 1 h, followed by calcination at a temperature of 450 °C for 2 h. For the characterization of sol-gel TiO2 films, the following analytic techniques were used: X-ray diffraction (XRD), differential thermal analysis (DTA), thermal gravimetry (TG), differential scanning calorimetry (DSC), diffuse reflectance spectroscopy (DRS), and energy dispersive X-ray spectroscopy (EDS). Sol-gel-derived Ce-TiO2 films were used for photocatalytic degradation of ciprofloxacin (CIP). The influence of the amount of Ce in TiO2 films, the duration of the photocatalytic decomposition, and the irradiation type (UV-A and simulated solar light) on the CIP degradation were monitored. Kinetics parameters (reaction kinetics constants and the half-life) of the CIP degradation, as well as photocatalytic degradation efficiency, were determined. The best photocatalytic activity was achieved by the TiO2 film doped with 0.08 wt.% Ce, under both UV-A and solar irradiation. The immobilized catalyst was successfully reused for three cycles under solar light simulator radiation, with changes in photocatalytic efficiency below 3%.

Gd-doped ZnFe2O4 multi-shell microspheres for enhancing photocatalytic H2 production or antibiotic degradation

It is anticipated to remove highly hazardous tetracycline antibiotic from aqueous solution photocatalytically by using Gd doped spinal ferrite. In this work, both ZnFe2O4 and Gd doped ZnFe2O4 photocatalysts were hydrothermally fabricated and characterized by different techniques. The spherical photocatalysts show extended photocatalytic removal efficiency under visible light. The optimized sample (ZnFe1.96Cd0.04O4) removes 78% antibiotic in 80 min. Moreover, under simulated solar light irradiation, the rate of hydrogen produced from water splitting photocatalysis with ZnFe1.96Cd0.04O4 reaches 230.4 μmol/(g·h). These increased activities are attributed to the increased specific surface area, the expanded light absorption range and the enhanced charge separation realized by doping Gd. According to the charge trapping study, both superoxide (•O2−) and hydroxyl radicals (•OH) were the major active species in the process of removing antibiotic. This research provides a feasible way to fabricate low cost photocatalysts for the eradication of highly hazardous pollutants from aqueous solution.

Evaluation of the simulation performance of WRF-Solar for a summer month in China using ground observation network data

Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels. However, the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation and prediction. Accurately simulating and predicting solar radiation and its variability are crucial for optimizing solar energy utilization. This study conducted simulation experiments using the WRF-Solar model from 25 June to 25 July 2022, to evaluate the accuracy and performance of the simulated solar radiation across China. The simulations covered the whole country with a grid spacing of 27 km and were compared with ground observation network data from the Chinese Ecosystem Research Network. The results indicated that WRF-Solar can accurately capture the spatiotemporal patterns of global horizontal irradiance over China, but there is still an overestimation of solar radiation, and the model underestimates the total cloud cover. The root-mean-square error ranged from 92.83 to 188.13 Wm−2 and the mean bias (MB) ranged from 21.05 to 56.22 Wm−2. The simulation showed the smallest MB at Lhasa on the Qinghai–Tibet Plateau, while the largest MB was observed in Southeast China. To enhance the accuracy of solar radiation simulation, the authors compared the Fast All-sky Radiation Model for Solar with the Rapid Radiative Transfer Model for General Circulation Models and found that the former provides better simulation.摘要准确模拟和预测太阳辐射及其变化对于优化太阳能利用至关重要. 本研究使用WRF-Solar模式对中国2022 年 6 月 25 日至 7 月 25 日的太阳辐射情况进行了深入模拟, 模式网格水平分辨率为27 km, 通过与中国生态系统研究网络 (CERN) 的地面观测网络数据的37个观测站点进行对比, 以评估模式性能. 结果表明: WRF-Solar模式能较好地捕捉到中国上空的辐照度GHI (Global Horizontal Irradiance) 的时空分布特征, 但存在高估太阳辐射量, 以及低估总云量的情况. 全国的总辐射模拟均方根误差范围为92.83–188.13 W m−2, 平均偏差范围为21.05–56.22 W m−2. 青藏高原拉萨站的偏差最小, 在中国东南部的偏差最大. 为了进一步提升太阳辐射模拟的精确度, 本研究还对比了FARMS与RRTMG辐射方案, 发现FARMS方案的模拟精度更高.

Hydrothermal preparation of magnetic recyclable In-doped MoO3/SrFe12O19 ternary nanocomposites with enhanced visible-light-driven photocatalytic performance

SrFe12O19 as a novel magnetic matrix has drawn increasing attention in photocatalysis. In the current study, a novel magnetically recoverable In-MoO3/SrFe12O19 ternary composite photocatalyst was fabricated with the hydrothermal method, and the photocatalytic activity was evaluated by degrading rhodamine B (RhB) solution through simulated solar irradiation. The results demonstrated that the outstanding degradation rate of RhB (96.5 %) could be achieved within 70 min when the mass ratio of both doped In and SrFe12O19 in the ternary composite photocatalyst was 5 % (5-IMS-5). The enhancement of the photocatalytic degradation performance was mainly related to the self-sensitization of RhB, the magnetic field effect of SrFe12O19, and the introduction of impurity energy levels by In doping. More importantly, the degradation rate of RhB by 5-IMS-5 was still up to 90.8 % after 4 times of recycling, verifying that the prepared ternary composite sample has good recyclability and stability. This study proves a novel ternary composite photocatalyst that can be used for organic wastewater treatment, and its photocatalytic degradation mechanism provides great reference significance for the synthesis of other SrFe12O19-based magnetic semiconductor photocatalysts.

TiO2-Alginate-Chitosan-Based Composites for Skin Tissue Engineering Applications.

The UV-B component of sunlight damages the DNA in skin cells, which can lead to skin cancer and premature aging. Therefore, it is necessary to use creams that also contain UV-active substances. Many sunscreens contain titanium dioxide due to its capacity to absorb UV-B wavelengths. In the present study, titan dioxide was introduced in alginate and chitosan-alginate hydrogel composites that are often involved as scaffold compositions in tissue engineering applications. Alginate and chitosan were chosen due to their important role in skin regeneration and skin protection. The composites were cross-linked with calcium ions and investigated using FT-IR, Raman, and UV-Vis spectroscopy. The stability of the obtained samples under solar irradiation for skin protection and regeneration was analyzed. Then, the hydrogel composites were assayed in vitro by immersing them in simulated body fluid and exposing them to solar simulator radiation for 10 min. The samples were found to be stable under solar light, and a thin apatite layer covered the surface of the sample with the two biopolymers and titanium dioxide. The in vitro cell viability assay suggested that the anatase phase in alginate and chitosan-alginate hydrogel composites have a positive impact.

Green synthesis and photocatalytic proficiency of tunable SnO2 nanostructures: unveiling environmental-friendly strategies for sustainable water remediation

This study demonstrates a proficient and eco-friendly synthesis of SnO2 nanostructures using a hydrothermal method, without the requirement of extra surfactants. The synthesis was systematically performed by adjusting the molar ratio of stannic chloride to sodium hydroxide and varying the pH settings. It was noted that the pH value rises according to the concentration of sodium hydroxide. A comprehensive analysis was performed to characterize the resulting nanostructures, which involved studying their structural features, chemical composition, morphology, and optical properties. An x-ray diffraction analysis showed that increasing the pH values resulted in a noticeable improvement in the crystalline structure and a decrease in the density of surface defects. The SnO2 nanostructures, synthesized using different pH settings, were subsequently assessed for their photocatalytic performance in the degradation of methylene blue dye under simulated solar irradiation. Surprisingly, the nanostructure produced at higher pH levels showed outstanding results, as 97% of the dye was broken down in just 70 min when exposed to simulated solar radiation. The analysis uncovered a maximum rate constant (k) value of 0.04 min−1, determined using pseudo first-order rate kinetics. In order to better understand the photodegradation process, scavenger experiments were performed to identify the active species involved. These investigations provided valuable insights into the complex mechanisms that drive the observed photocatalytic activity. This study not only enhances the progress of SnO2 nanostructures but also highlights their potential as strong and environmentally friendly materials for effective photocatalytic applications.

Efficient peracetic acid activation by high-index facets of Cu2O under simulated solar light: The crucial role of uncoordinated Cu atoms

Tuning the facets of transition-metal catalysts to achieve effective micropollutant removal via peracetic acid (PAA) activation is a promising approach. However, within this process, the correlation between PAA activation and the atomic arrangement of the exposed facets is ambiguous. Herein, we present a comprehensive study wherein a series of Cu2O materials, with typical high-index facets ({211}, {311}, and {332}) and low-index facets ({100}, {110}, and {111}), were synthesized. These materials were used to investigate facet-dependent PAA activation for tetracycline (TC) degradation under simulated solar light irradiation. The results demonstrate that Cu2O with high-index {332} facets exhibit the optimal TC degradation (96.65 % within 20 min), and its kobs values are 1.52 and 2.01 times those of Cu2O with {311} and {211} facets, respectively. Detailed identification of the active species proved that •OH, 1O2, and the electron transfer process induced by the reactive Cu (I)–PAA* complexes were involved in TC degradation. In contrast to the {211} and {311} facets, PAA demonstrated a heightened tendency for adsorption and activation into active species on the {332} facets because of the denser uncoordinated Cu atoms. In addition, the facet heterojunction composed of {332} and {100} facets was conducive to the separation of photogenerated electron-hole pairs and charge migration, thus promoting the Cu(II)/Cu(I) cycle. In the practical applicability evaluation, Cu2O with {332} facets effectively removed multiple pollutants as well as actual pharmaceutical wastewater. This study provides a novel strategy for PAA activation by regulating the exposed facets of the catalyst.

O06 Naïve human keratinocytes initiate a chromatin-protective mechanism in response to ultraviolet radiation through the upregulation of histone deacetylase 5

Abstract Introduction and aims During normal development and throughout life, epigenetic changes arise in response to an individuals’ behaviour and environmental exposures. Histone deacetylases (HDACs) are chromatin-modifying enzymes that regulate gene expression and their activity and expression in primary human keratinocytes alters with increasing age. Solar ultraviolet radiation (UVR) is a major causative factor of skin ageing, but how this factor affects HDAC expression and activity is largely unknown. We aimed to determine how UVR exposure affects HDAC expression and activity in primary human keratinocytes. Methods Normal human epidermal keratinocytes (NHEKs) from juvenile (aged 1–6 years; n = 3), middle-aged (56–61 years; n = 3) and aged (83–85 years; n = 3) donors were exposed to solar-simulated radiation (SSR) and HDAC abundance and activity were assayed. Results Exposure to SSR significantly increased HDAC activity in primary NHEKs irrespective of donor age (P < 0.05). However, Western blotting for HDAC abundance revealed that there was a differential response to SSR exposure across age groups; juvenile NHEKs expressed significantly more HDAC5 in response to SSR (P < 0.05) than cells from middle-aged or aged donors. Furthermore, following SSR exposure of juvenile NHEKs, the cellular localization of HDAC5 was redistributed to the nucleus from the cytoplasm. Dual immunofluorescence staining revealed that those NHEKs with nuclear HDAC5 expression were also positive for p16INK4a, a robust marker of cellular senescence (P < 0.01). Conclusions Our Results suggest that naïve human keratinocytes are responsive to UVR exposure and appear to initiate a chromatin-protective mechanism through the upregulation of HDAC5 to prevent gene expression of damaged DNA.

Unlocking the Potential of Bi2S3-Derived Bi Nanoplates: Enhanced Catalytic Activity and Selectivity in Electrochemical and Photoelectrochemical CO2 Reduction to Formate.

Various electrocatalysts are extensively examined for their ability to selectively produce desired products by electrochemical CO2 reduction reaction (CO2RR). However, an efficient CO2RR electrocatalyst doesn't ensure an effective co-catalyst on the semiconductor surface for photoelectrochemical CO2RR. Herein, Bi2S3 nanorods are synthesized and electrochemically reduced to Bi nanoplates that adhere to the substrates for application in the electrochemical and photoelectrochemical CO2RR. Compared with commercial-Bi, the Bi2S3-derived Bi (S-Bi) nanoplates on carbon paper exhibit superior electrocatalytic activity and selectivity for formate (HCOO-) in the electrochemical CO2RR, achieving a Faradaic efficiency exceeding 93%, with minimal H2 production over a wide potential range. This highly selective S-Bi catalyst is being employed on the Si photocathode to investigate the behavior of electrocatalysts during photoelectrochemical CO2RR. The strong adhesion of the S-Bi nanoplates to the Si nanowire substrate and their unique catalytic properties afford exceptional activity and selectivity for HCOO- under simulated solar irradiation. The selectivity observed in electrochemical CO2RR using the S-Bi catalyst correlates with that seen in the photoelectrochemical CO2RR system. Combined pulsed potential methods and theoretical analyses reveal stabilization of the OCHO* intermediate on the S-Bi catalyst under specific conditions, which is critical for developing efficient catalysts for CO2-to-HCOO- conversion.

Novel A–D–A Type Naphthalenediimide Supramolecule for H2O2 Photosynthesis with Solar‐to‐Chemical Conversion 1.03%

AbstractOrganic supermolecules have shown great promise for photocatalytic hydrogen peroxide (H2O2) production. However, the limitation of intramolecular charge separation efficiency is still a crucial scientific problem. In this study, a novel acceptor–donor–acceptor (A–D–A) type naphthalenediimide supramolecule (SA‐NDI) is successfully designed for overcoming fundamental issues in organic supermolecule. Composed of one electron‐rich core (naphthalenediimide) and two electron‐poor units (aminopyridine), the supramolecule possesses strong intramolecular charge transfer ability. Meanwhile, the SA‐NDI has an obviously stronger internal electric field, which is 2.83 times higher than that of D–A type supramolecule. The A–D–A type SA‐NDI efficiently accelerates charge separation, so that the intramolecular electron quickly migrates to the acceptor for a two‐electron oxygen reduction reaction. The SA‐NDI supramolecule shows excellent H2O2 accumulation ability (13.7 mm) and stable cyclic time above 120 h. Meanwhile, the catalyst exhibits a superior solar‐to‐chemical conversion efficiency of 1.03% under simulated solar irradiation. This work provides an entirely new idea to design an organic supramolecule with an efficient intramolecular charge transfer monomer.

Fabricating of multi-interfacial charge transfer paths in the novel noble-metal-free Ni2P/ZnS/g-C3N4 ternary nanocomposite for enhanced charge separation and transfer for photocatalytic H2 generation

This work reports the development of a novel Ni₂P/ZnS/C₃N₄ ternary nanocomposite photocatalyst for efficient hydrogen (H₂) production. The nanocomposite was synthesized using a facile approach combining hydrothermal synthesis, ball milling, and wet impregnation methods then characterized using various techniques. Photocatalytic H₂ generation was evaluated under simulated solar irradiation with sodium sulfite (Na₂SO₃)/sodium sulfide (Na₂S) as sacrificial reagents. The optimized 3NP/ZnS-8CN (3% Ni2P/ZnS/8% C3N4) catalyst displayed an exceptional H₂ generation rate of 3991 µmol h⁻¹ g⁻¹, exceeding both pristine g-C3N4 (by 10.2 times) and 3% Ni2P/ZnS (by 1.2 times). This represents the highest reported rate of H₂ evolution for a graphitic carbon nitride (g-C3N4) based ternary nanocomposite under simulated solar radiation. Furthermore, the 3NP/ZnS-8CN photocatalyst exhibited good stability over four reaction cycles. This study provides valuable insights for designing efficient noble metal-free g-C3N4-based photocatalysts, which can significantly contribute to the transition to solar-driven hydrogen generation. The results of this study suggest that the synthesized composite materials hold significant promise for the advancement of new energy technologies.

Selective Photocatalytic CO2 Reduction Through Plasmonic Z‐Scheme Ag‐Bi2O3‐ZnO Heterostructures

AbstractCombination of plasmonic noble metal with semiconductors offers a promising and potential solar energy harvesting and conversion route. Herein, plasmonic Z‐scheme Ag‐Bi2O3‐ZnO (AgBZ) heterostructure is designed and synthesized via solution combustion and photo‐deposition method. Metallic Ag nanoparticles (NPs) were deposited over Bi2O3‐ZnO heterostructure; thus, they exhibit strong visible light absorption owing to surface plasmon resonance (SPR). The photocatalytic efficiency of the synthesized catalysts is investigated by the photocatalytic CO2 reduction to fuels under simulated solar light irradiation. The present system has shown an outstanding photocatalytic CO2 reduction and excellent selectivity of CO. The evolved rate of CO fuel, the amount of CO produced per unit time, over optimized Ag‐Bi2O3‐ZnO (3AgBZ) heterostructures was (96.74 μmol g−1/h) which was approximately 12 times larger than that of Bi2O3‐ZnO (0AgBZ) and 49‐fold than the quantity of evolved CO fuels over pure ZnO photocatalyst. The percentage of evolved CO to CH4 fuels over optimized Ag‐Bi2O3‐ZnO (3AgBZ) heterostructures was about 50 : 1compared to that of 2 : 3 over Bi2O3‐ZnO (0AgBZ). The great improvement and the high selectivity would be ascribed to the synergistic effect of metallic surface plasmon resonance and the Z‐scheme charges transfer system. This work would open a window to construct a single photocatalyst with different charge separation systems and excellent CO2 reduction selectivity. Finally, the mechanism for the enhanced photocatalytic performance by the synergistic effect was described and discussed.

0D/1D CuO-Cu2O/ZnO p-n heterojunction with high photocatalytic activity for the degradation of dyes and Naproxen

The development of highly active photocatalysts with broad spectrum response is of paramount importance for photocatalytic applications. Herein, heterostructured CuO-Cu2O/ZnO photocatalysts were prepared in a single step and under mild conditions using a photodeposition process which allows to deposit CuO-Cu2O particles with an average size of ca. 2.4 nm on the surface of ZnO nanorods. The p-n heterojunction built between CuO-Cu2O and ZnO allows to increase both the visible light response of the photocatalyst and the charge separation. The CuO-Cu2O(10%)/ZnO catalyst exhibits the highest activity for the degradation of dyes (Rhodamine B and Remazol Brilliant Blue R) and of Naproxen under simulated solar light irradiation. Based on scavenging experiments, holes, superoxide radicals O2●- and singlet oxygen 1O2 are the dominant species involved in the photocatalytic degradation and a mechanism is proposed. Due to its high stability and photocatalytic performance in various water matrices, the CuO-Cu2O(10%)/ZnO nanohybrid is of high potential for the large scale remediation of organic pollutants in wastewater.

Conjugated Polymer/Recombinant Escherichia coli Biohybrid Systems for Photobiocatalytic Hydrogen Production.

Biohybrid photocatalysts are composite materials that combine the efficient light-absorbing properties of synthetic materials with the highly evolved metabolic pathways and self-repair mechanisms of biological systems. Here, we show the potential of conjugated polymers as photosensitizers in biohybrid systems by combining a series of polymer nanoparticles with engineered Escherichia coli cells. Under simulated solar light irradiation, the biohybrid system consisting of fluorene/dibenzo [b,d]thiophene sulfone copolymer (LP41) and recombinant E. coli (i.e., a LP41/HydA BL21 biohybrid) shows a sacrificial hydrogen evolution rate of 3.442 mmol g-1 h-1 (normalized to polymer amount). It is over 30 times higher than the polymer photocatalyst alone (0.105 mmol g-1 h-1), while no detectable hydrogen was generated from the E. coli cells alone, demonstrating the strong synergy between the polymer nanoparticles and bacterial cells. The differences in the physical interactions between synthetic materials and microorganisms, as well as redox energy level alignment, elucidate the trends in photochemical activity. Our results suggest that organic semiconductors may offer advantages, such as solution processability, low toxicity, and more tunable surface interactions with the biological components over inorganic materials.

Disposable indicator card for personal monitoring of solar exposure

Although the Earths atmosphere provides substantial reduction of the incident radiant power in the most harmful spectral ranges, excessive exposure of untrained and/or unprotected human skin to solar radiation can easily result into acute and chronic adverse effects onto human skin. In order to reduce these effects, a simple tool for monitoring the incident radiant dose is proposed. We report on the design, development, lab scale fabrication, calibration and the roll-to-roll printing production of a photosensitive indicator cards intended for personal monitoring of solar exposure to which the user has been subjected. Two types of cards are being discussed. The first one is supposed as high sensitive one with a dose response to 1 and 2 SEDs, the second one is a less sensitive with a dose response to 3 and 4 SEDs. The calibration of the cards was performed with polychromatic simulated solar radiation without determining the spectral response, therefore we refer to the device as indicator card, not dosimeters. Moreover, properties of the photosensitive formulation employed for the fabrication of the indicator are presented alongside with the calibration of the printed indicator to dermatologically relevant values of the received solar exposure dose. Special attention is also paid to the large-scale practical production of such indicators by the roll-to-roll printing technology. Mechanical properties, stability, durability, practical utilisation, and other features are critically assessed.

In-situ construct CuInS2/Bi/Bi2MoO6 S-scheme/Schottky dual heterojunctions catalyst for enhanced photocatalytic degradation of diclofenac sodium

In this paper, the S-scheme/Schottky heterojunction photocatalyst (CuInS2/Bi/Bi2MoO6, CIS/Bi/BMO) was successfully constructed via a facile in-situ solvothermal method, aimed at enhancing its photocatalytic performance. The results of the study on the photocatalytic degradation of diclofenac sodium (DCF) under simulated solar light irradiation revealed that the as-prepared composite exhibited remarkable catalytic efficiency in comparison to the pristine Bi2MoO6 and CuInS2. The plasmonic bismuth (Bi) was formed during the solvothermal process. Subsequently, CuInS2 and Bi were grown on the surface of Bi2MoO6 leading to forming CIS/BMO S-scheme heterojunction, along with a Schottky junction between Bi and Bi2MoO6. The use of ethylene glycol as a support was the main reason for the significant improvement in photocatalytic efficiency in the degradation of DCF. Moreover, the probable photocatalytic mechanisms for the degradation of DCF had been proposed based on the active species quenching experiments. The eleven degradation products were detected by HPLC-MS, and the degradation reaction pathway of DCF was deduced. Additionally, the CIS/Bi/BMO photocatalyst exhibited a consistently high removal rate after four cycles. This study proposes a new strategy for designing efficient S-scheme/Schottky heterojunction photocatalysts for solar energy conversion.

Thermal treatment impact on the evolution of active phases in layered double hydroxide-based ZnCr photocatalysts: Photodegradation and antibacterial performance

Abstract This study investigated the influence of thermal treatment on the photocatalytic performance of ZnCr layered double hydroxide-based mixed metal oxides in the degradation of methylene blue and brilliant cresyl blue organic dyes under simulated solar light irradiation. The photocatalysts were synthesized using a simple coprecipitation method and subjected to thermal treatment at temperatures ranging from 100°C to 900°C. Additionally, the study explored the antibacterial activity against Escherichia coli and Staphylococcus aureus using a novel antibacterial experimental setup. It not only involved the introduction of ZnCr samples into BioPeptone/prepared cell suspension to enhance photocatalyst–bacteria cell contact but also included research on antibacterial activity induced by solar irradiation and also in the absence of light, providing crucial insights into photocatalytic antibacterial activity of ZnCr photocatalysts. Despite satisfactory efficiencies observed for all thermally treated ZnCr samples (removal efficiency ranging from 40% to 90%), ZnCr 900 (thermally treated at 900°C) exhibited exceptional performance, achieving nearly 100% removal efficiency and complete growth inhibition for both bacteria. Integrating these findings with structural and textural characterization data, as well as kinetic studies, our comprehensive analysis enhances the understanding of structure-dependent photocatalytic activities. These insights open possibilities for the application of ZnCr photocatalysts in water purification and environmental remediation.

Enhancing photocatalytic efficiency of type II V2O5/TiO2 heterojunctions for malachite green dye using solar simulator irradiation

Photocatalytic responses and synergistic effects of V2O5, TiO2, and V2O5/TiO2 heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V2O5/TiO2 heterostructures increases with higher TiO2 concentrations. These findings enhance our understanding of the agglomerated heterostructures of V2O5/TiO2, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V2O5/TiO2 heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.

Photocatalytic activity and mechanism of YMnO3/NiO photocatalyst for the degradation of oil and gas field wastewater.

One-step hydrothermal method has been used to synthesize YMnO3@NiO (YMO@NO) photocatalysts with high photocatalytic activity for the degradation of oil and gas field wastewater under simulated solar irradiation. Through various characterization methods, it has been confirmed that the YMO@NO photocatalyst comprises only YMO and NO, without any other impurities. The microstructure characterization confirmed that the YMO@NO photocatalyst was composed of large squares and fine particles, and heterojunction was formed at the interface of YMO and NO. The optical properties confirm that the YMO@NO photocatalyst has high UV-vis optical absorption coefficient, suggesting that it has high UV-vis photocatalytic activity. Taking oil and gas field wastewater as degradation object, YMO@NO photocatalyst showed the highest photocatalytic activity (98%) when the catalyst content was 1.5g/L, the mass percentage of NO was 3%, and the irradiation time was 60min. Capture and stability experiments confirm that the YMO@NO photocatalyst is recyclable and electrons, holes, hydroxyl radicals and superoxide radicals play major roles in the photocatalysis process. Based on experiments and theoretical calculations, a reasonable photocatalytic mechanism of the YMO@NO photocatalyst is proposed.

Construction of TiO2@Cu2O-CuS heterostructures integrating RGO for enhanced full-spectrum photocatalytic degradation of organic pollutants

This study presents the development and optimization of TiO2@Cu2O-CuS heterostructures, enhanced with reduced graphene oxide (RGO), for efficient photocatalytic degradation of organic pollutants, focusing on imidacloprid. Two configurations, TiO2/RGO/Cu2O-CuS and Cu2O-CuS/RGO/TiO2, are explored to highlight the impact of material layering on photocatalytic efficiency. The strategic integration of RGO optimizes charge transfer, crucial for photocatalysis. Comprehensive characterization techniques, such as X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman spectroscopy, and Nitrogen adsorption-desorption isotherms, provide insights into the crystalline structure, morphology, surface chemistry, and textural properties of the heterostructures. The TiO2/RGO/Cu2O-CuS configuration significantly outperforms its counterpart in photocatalytic activity under full-spectrum (UV–VIS–IR) illumination, due to improved charge carrier dynamics and synergistic interactions between the composite materials. Remarkably, the TiO2/RGO/Cu2O-CuS assembly achieved over 95 % degradation of imidacloprid under simulated solar irradiation, marking a breakthrough in solar spectrum utilization for photocatalysis and exhibits promising recyclability, maintaining its high photocatalytic efficiency even after multiple degradation cycles, highlighting its potential for sustainable pollutant removal applications. Additionally, this configuration demonstrates a twofold increase in degradation efficiency compared to separate UV and VIS irradiations, emphasizing its rapid pollutant removal capability. This research underscores the critical role of material layer sequencing in developing high-efficiency photocatalytic systems and marks a significant advancement in environmental remediation technologies that harness renewable energy sources.