Photocatalytic Performance Research Articles

Magnetic separation, sunlight-driven photocatalytic activity, and antibacterial studies of Sm-doped Co0.33Mg0.33Ni0.33Fe2O4 nanoparticles.

Magnetic nanoparticles have emerged as a promising tool for wastewater treatment due to their unique properties. In this regard, Co0.33Mg0.33Ni0.33SmxFe2-xO4 (0.00 x 0.08) nanoparticles were prepared to examine their magnetic separation efficiency (MSE), photocatalytic, antibacterial, and antibiofilm performances. Pure nanoparticles, having the highest saturation magnetization (Ms = 31.87emu/g), exhibit the highest MSE, where 95.6% of nanoparticles were separated after 20min of applying a magnetic field of 150 mT. The catalytic performance of the prepared samples is examined by the photodegradation of rhodamine B (RhB) dye exposed to direct sunlight radiation. Improved photocatalytic activity is exhibited by Co0.33Mg0.33Ni0.33Sm0.04Fe1.96O4 nanoparticles, labeled as Sm0.04, where the rate of the degradation reaction is enhanced by 4.1 times compared to pure nanoparticles. Rising the pH and reaction temperature improves the rate of the photodegradation reaction of RhB. The incorporation of 15 wt% reduced graphene oxide (rGO) with Sm0.04 enhanced the rate of the reaction by 1.7 and 2.4 times compared with pure Sm0.04 sample and rGO, respectively. The antibacterial and antibiofilm activities against Escherichia coli, Leclercia adecarboxylata, Staphylococcus aureus, and Enterococcus faecium are assessed by the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) broth microdilution, the agar well diffusion, the time-kill assays, the biofilm formation, and destruction assays. The bacteria used in these assessments are isolated from wastewater. The nanoparticles exhibit a bacteriostatic activity, with a better effect against the Gram-positive isolates. Co0.33Mg0.33Ni0.33SmxFe2O4 (x = 0.00) nanoparticles have the best effect. The effect is exerted after 2-3h of incubation. Gram-positive biofilms are more sensitive to nanoparticles.

Indoor-Light-Activated Blue TiO2-Molecule-WO3 Visible Photocatalyst for Antibacterial Performance against Escherichia coli.

Currently used visible light catalysts either operate with high-power light sources or require prolonged periods of time for catalytic reactions. This presents a limitation regarding facile application in indoor environments and spaces frequented by the public. Furthermore, this gives rise to elevated power consumption. Here, we enhance photocatalytic performance with blue TiO2 and WO3 complexes covalently coupled through an organic molecule, 3-mercaptopropionic acid, under indoor light. Antibacterial experiments against 108 CFU/mL Escherichia coli (E. coli) suspensions were conducted under indoor light exposure conditions. They showed a sterilization effect of almost 90% within 70 min and nearly 100% after 110 min. The complex generates reactive oxygen species (ROS), such as •OH and O2•-, under natural air conditions. We also showed that h+ and •OH are important for sterilizing E. coli using common scavengers. This research highlights the potential of these complexes to generate ROS, effectively playing a crucial role in antibacterial effects under indoor light.

Elucidating Structural Disorder in Ultra-Thin Bi-Rich Bismuth Oxyhalide Photocatalysts.

Advancing the field of photocatalysis requires the elucidation of structural properties that underpin the photocatalytic properties of promising materials. The focus of the present study is layered, Bi-rich bismuth oxyhalides, which are widely studied for photocatalytic applications yet poorly structurally understood, due to high levels of disorder, nano-sized domains, and the large number of structurally similar compounds. By connecting insights from multiple scattering techniques, utilizing electron-, X-ray- and neutron probes, the crystal phase of the synthesized materials is allocated as layered Bi24O31X10 (X = Cl, Br), albeit with significant deviation from the reported 3Dcrystalline model. The materials comprise anisotropic platelet-shaped crystalline domains, exhibiting significant in-plane ordering in two dimensionsbut disorder and an ultra-thin morphology in the layer stacking direction. Increased synthesis pH tailored larger, more ordered crystalline domains, leading to longer excited state lifetimes determined via femtosecond transient absorption spectroscopy (fs-TAS). Although this likely contributes to improved photocatalytic properties, assessed via the photooxidation of benzylamine, increasing the overall surface area facilitated the most significant improvement in photocatalytic performance. This study, therefore, enabled both phase allocation and a nuanced discussion of the structure-property relationship for complicated, ultra-thin photocatalysts.

Single-Atom based Metal-Organic Framework Photocatalysts for Solar-Fuel Generation.

The growing demand for fossil fuels and subsequent CO2 emissions prompted a search for alternate sources of energy and a reduction in CO2. Photocatalysis driven by solar light has been found as a potential research area to tackle both these problems. In this direction, SAC@MOF (Single-atom loaded MOFs) photocatalysis is an emerging field and a promising technology. The unique properties of single-atom catalysts (SACs), such as high catalytic activity and selectivity, are leveraged in these systems. Photocatalysis, focusing on the utilization of Metal-Organic Frameworks (MOFs) as platforms for creating single-atom catalysts (SACs) characterized by metal single-atoms (SAs) as their active sites, are noted for their unparalleled atomic efficiency, precisely defined active sites, and superior photocatalytic performance. The synergy between MOFs and SAs in photocatalytic systems is meticulously examined, highlighting how they collectively enhance photocatalytic efficiency. This review examines SAC@MOF development and applications in environmental and energy sectors, focusing on synthesis and stabilization methods for SACs on MOFs and also characterization techniques vital for understanding these catalysts. The potential of SAC@MOF in CO2 Photoreduction and Photocatalytic H2 evolution is highlighted, emphasizing its role in green energy technologies and advances in materials science and Photocatalysis.

Construction of Z‐scheme 1T/2H‐MoS2/CdS for improving photocatalytic degradation of antibiotic residues

Abstract1T/2H‐MoS2/CdS composite was effectively prepared by a two‐step hydrothermal method, which greatly improved the photocatalytic degradation efficiency of tetracycline hydrochloride and photocatalytic cycle stability compared with pristine 1T/2H‐MoS2. The highest photodegradation efficiency of 70.8% is achieved when the molar ratio of 1T/2H‐MoS2 to cadmium sulfide is 1:4. The capture experiment indicates that hydroxyl radical (⋅OH) and superoxide radical (⋅O2−) play a role in the photocatalytic degradation process. A Z‐type heterojunction may be formed on the 1T/2H‐MoS2/CdS composite based on a series of analyses, which improves the photocatalytic performance effectively via expanding the range of light response and promoting the separation of photogenerated electrons and holes. This work provides an alternative to constructing novel Z‐scheme photocatalysts with high performance in the absence of noble metals.

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

Abstract 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 (XRD) 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 (MB) 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 minutes 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.

Facile Fabrication of SrTiO3/In2O3 on Carbon Fibers via a Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production

Photocatalytic water splitting by semiconductors is considered a promising and cost-effective method for achieving sustainable hydrogen production. In this study, a CF/SrTiO3/In2O3 photocatalytic material with a double-layer core–shell structure was developed. The experimental results indicated that the produced CF/SrTiO3/In2O3 composite fiber displayed superior photocatalytic hydrogen production performance, achieving a hydrogen evolution rate of approximately 320.71 μmol/g·h, which is roughly seven times higher than that of the CF/SrTiO3 fiber alone. The enhanced photocatalytic activity of the CF/SrTiO3/In2O3 fiber can be attributed to the heterojunction structure enriched with oxygen vacancies. It was found that these oxygen vacancies created defective states that served as traps for photogenerated electrons, facilitating their migration to the surface defect states and enabling the reduction of H+ in water to produce hydrogen. Furthermore, the synergy between the heterojunction structure and the conductivity of the carbon fiber promoted the generation and migration of photogenerated electrons, reduced the recombination of photogenerated electron–hole pairs, and ultimately improved photocatalytic hydrogen production. This study presents a new approach for designing efficient photocatalysts with surface oxygen vacancies on carbon fibers, providing new insights into the sustainable application of photocatalysts.

Preparation, characterization, and mechanism for enhanced photocatalytic performance in Bi1-xSmxFeO3 nanoparticles

Preparation, characterization, and mechanism for enhanced photocatalytic performance in Bi1-xSmxFeO3 nanoparticles

Sustainable Sol‐Gel Approach for Visible Light‐Responsive Titanium Dioxide Nanoparticles in Efficient Diazinon Removal

AbstractThis study addresses water pollution challenges by employing photocatalysis as an effective solution. Titanium dioxide (TiO2) with unique characteristics is widely utilized in this approach. However, the design of nanosized TiO2 particles is crucial for enhancing photocatalytic performance during diazinon's photodegradation. As such, the TiO2 nanoparticles (NPs) were synthesized via the green sol‐gel method in this study, exhibit a mixed anatase‐brookite phase, a small particle size of 11.17 nm, and lower bandgap energy (3.00 eV) than pure anatase TiO2 of 3.20 eV, rendering them active under visible light. DFTB calculation was deployed to investigate the role of oxygen vacancies in reducing the bandgap energy. Experimentally measured (3.00 eV) and computationally (2.812 eV) determined bandgap energies align well. The TiO2 NPs demonstrate significant photocatalytic efficacy, degrading 73.3 % of diazinon within 210 min under sunlight, with a mineralization degree of 43.50 %, and 2‐isopropyl‐6‐methylpyrimidin‐4‐ol (IMP) was detected as the intermediate product. The photodegradation follows first‐order kinetics, and adsorption isotherm analysis fits the Langmuir model. ⋅O2− is identified as the predominant reactive oxygen species in the diazinon's photodegradation. Hence, the synthesized TiO2 NPs offer good reusability, maintaining a degradation efficiency of 67.4 % even after five cycles, showing good potential for wastewater treatment applications.

Synergistic Effects of MOFs and Noble Metals in Photocatalytic Reactions: Mechanisms and Applications.

Photocatalytic technology can efficiently convert solar energy to chemical energy and this process is considered as one of the green and sustainable technology for practical implementation. In recent years, metal-organic frameworks (MOFs) have attracted widespread attention due to their unique advantages and have been widely applied in the field of photocatalysis. Among them,noblemetals have contributed significant advances to the field as effective catalysts in photocatalytic reactions. Importantly, noblemetals can also form a synergistic catalytic effect with MOFs to further improve the efficiency of photocatalytic reactions.However, how to precisely control the synergistic effect between MOFs and noblemetals to improve the photocatalytic performance of materials still needs to be further studied.In this review, the synergistic effects of MOFs and noblemetal catalysts in photocatalytic reactionsare firstly summarizedin terms of noblemetal nanoparticles, noblemetal monoatoms, noblemetal compounds, and noblemetal complexes, and focus on the mechanisms and advantages of these synergistic effects, so as to provide useful guidance for the further research and application of MOFs and contribute to the development of the field of photocatalysis.

Constructing Robust Interfacial Chemical Bond Enhanced Charge Transfer in S‐Scheme 3D/2D Heterojunction for CO2 Photoreduction

AbstractA stable ZnTe@Cs3Sb2I9 catalyst with 3D/2D‐hollow‐composite structure is constructed for CO2 photocatalytic reduction via the in situ growth of Cs3Sb2I9 nanosheets on hollow ZnTe microspheres using lattice matching. The formed Tellurium‐Antimony (Te─Sb) bonds improved the poor contact at the heterojunction interface, effectively promoted charge separation, and successfully suppressed photocorrosion. The unique core‐shell structure not only strengthens light absorption but also improves CO2 adsorption capacity. Consequently, the S‐scheme heterojunction with the synergistic effect of chemical bonds and 3D/2D‐hollow‐composite structure significantly enhances photocatalytic performance. The ZnTe@Cs3Sb2I9 photocatalyst offers a CO selectivity of 90.5%, which is higher than that of pure ZnTe (22.9%) and Cs3Sb2I9 (56.9%). This structure holds great promise for practical applications in CO2 photocatalytic reduction.

Nitrogen-doped carbon quantum dot as electron acceptor anchored on graphitic carbon nitride nanosheet for improving rhodamine B degradation

Carbon quantum dots (CQDs) hold significant promise for wastewater treatment because of their remarkable attributes, including robust stability, outstanding biocompatibility, minimal toxicity, superior water dispersibility, cost-effective production, and exceptional photo-stability.In this study, CQDs were synthesized using microplasma and tested for the degradation of rhodamine B (RhB) (5 mg/L) under different conditions, with a Solar simulator and UVA illumination. Specifically, graphitic carbon nitride nanosheets (NCN) in conjugation with carbon quantum dots (NCN@CQD) were prepared with different amounts of CQD. The synthesized CQD, NCN, and NCN@CQD underwent characterization using various compositional and structural analytical techniques. The results show that nitrogen species were effectively incorporated into the CQDs framework and CQDs are anchored on NCN forming NCN@CQD successfully. Subsequently, all samples were then investigated in degrading Rhodamin B, RhB, to assess the photocatalytic activity. The results reveal that the presence of CQDs substantially improved the photocatalytic efficiency of NCN. Specifically, the CQDs anchored on NCN exhibited a substantial enhancement in the photoactivity for RhB decomposition under a solar light simulator, surpassing that of pure NCN. The amount of CQD in the NCN@CQD sample exerted a strong influence on the photocatalytic activity. All NCN@CQD samples exhibited remarkable enhancements in both adsorption and photocatalytic performance compared to pure CQD and NCN samples. In an optimization study, a best NCN@CQ photocatalyst was identified, showing a 40 % enhancement of photocatalytic efficiency compared to the use of NCN alone. A visible light photocatalytic activity of 91 % can be attained within 150 min, exhibiting a reaction rate constant of 0.0135 min−1 toward RhB decomposition, which was double as for the individual NCN (0.0067 min−1). The boosted photocatalytic activity resulting from the synergistic effect between NCNs and CQDs can be attributed to the efficient function of CQD as an electron acceptor. The proposed mechanism of photocatalytic degradation of RhB is illustrated in detail.

Insights into the effect of Ni doping on In2S3 for enhanced activity and selectivity of photocatalytic CO2 reduction

The limited photocatalytic CO2 reduction performance mainly lies in the low utilization of photogenerated electrons during the reaction. In this work, we developed the defect level within the Ni-doped In2S3 nanotube photocatalysts via a simple solvothermal method to increase the available amount of photogenerated electrons for enhanced photocatalytic CO2 reduction performance than the pristine In2S3. The introduction of Ni element into the lattice of In2S3 could significantly improve the photocatalytic activity and selectivity without destruction of the nanotube structure of In2S3. The yield of CO reaches 243.2 μmol/g/h under visible light, which is the highest reported value among In2S3 photocatalysts, and is 8.2 times more than the pure In2S3. Moreover, by modulating the doping amount of Ni element, the selectivity of CO varied from 27.7% to 51.0%. Further characterizations suggest that the doping of Ni element altered the electronic bandgap arrangement of In2S3, where the position of the conduction band is conducive to the activation of CO2 molecules. Moreover, the defect level resulting from Ni-doping not only facilitates the separation of photoexcited electron-hole pairs but also suppresses the recombination of electrons and holes. This study provides an available and reliable strategy for enhancing the photocatalytic CO2 reduction performance of related sulfide photocatalytic materials in future studies.

Oxygen Vacancies Trigger Rapid Charge Transport Channels at the Engineered Interface of S-scheme Heterojunction for Boosting Photocatalytic Performance.

Although oxygen vacancies (Ovs) have been intensively studied in single semiconductor photocatalysts, exploration of intrinsic mechanisms and in-depth understanding of Ovs in S-scheme heterojunction photocatalysts are still limited. Herein, a novel S-scheme photocatalyst made from WO3-Ov/In2S3 with Ovs at the heterointerface is rationally designed. The microscopic environment and local electronic structure of the S-scheme heterointerface are well optimized by Ovs. Femtosecond transient absorption spectroscopy (fs-TAS) reveals that Ovs trigger additional charge movement routes and therefore increase charge separation efficiency. In addition, Ovs have a synergistic effect on the thermodynamic and kinetic parameters of S-scheme photocatalysts. As a result, the optimal photocatalytic performance is significantly improved, surpassing that of single component WO3-Ov and In2S3 (by 35.5 and 3.9 times, respectively), as well as WO3/In2S3 heterojunction. This work provides new insight into regulating the photogenerated carrier dynamics at the heterointerface and also helps design highly efficient S-scheme photocatalysts.

Oxygen Vacancies Trigger Rapid Charge Transport Channels at the Engineered Interface of S‐scheme Heterojunction for Boosting Photocatalytic Performance

Although oxygen vacancies (Ovs) have been intensively studied in single semiconductor photocatalysts, exploration of intrinsic mechanisms and in‐depth understanding of Ovs in S‐scheme heterojunction photocatalysts are still limited. Herein, a novel S‐scheme photocatalyst made from WO3‐Ov/In2S3 with Ovs at the heterointerface is rationally designed. The microscopic environment and local electronic structure of the S‐scheme heterointerface are well optimized by Ovs. Femtosecond transient absorption spectroscopy (fs‐TAS) reveals that Ovs trigger additional charge movement routes and therefore increase charge separation efficiency. In addition, Ovs have a synergistic effect on the thermodynamic and kinetic parameters of S‐scheme photocatalysts. As a result, the optimal photocatalytic performance is significantly improved, surpassing that of single component WO3‐Ov and In2S3 (by 35.5 and 3.9 times, respectively), as well as WO3/In2S3 heterojunction. This work provides new insight into regulating the photogenerated carrier dynamics at the heterointerface and also helps design highly efficient S‐scheme photocatalysts.

A novel type-II–II heterojunction for photocatalytic degradation of LEV based on the built-in electric field: carrier transfer mechanism and DFT calculation

Heterojunctions play a crucial role in improving the absorption of visible light and performance of photocatalysts for organic contaminants degradation in water. In this work, a novel type-II–II Ag2CO3/Bi2WO6 (AB) heterojunction was synthesized by hydrothermal reaction and in situ-precipitation methods. The mechanisms of charge transfer and carrier separation at the interface of heterojunctions and the influence on the photocatalytic activity were investigated. The degradation of levofloxacin (LEV) under visible light irradiation was employed to evaluate the photocatalytic performance of AB. The results showed that 85.4% LEV was degraded by AB, which was 1.38 and 1.39 times higher than that of Bi2WO6 and Ag2CO3, respectively. The work functions of the different crystal planes in the AB heterojunction, which was calculated by density functional theory, are a significant difference. The Fermi energy (Ef) of Ag2CO3 (− 6.005 eV) is lower than Bi2WO6 (− 3.659 eV), but the conduction band (CB) is higher. Therefore, using AB heterojunctions as an example, the research explored the mechanism of type-II–II which CB and Ef of one semiconductor cannot simultaneously surpass those of another material, based on the built-in electric field theory. Through this analysis, a deeper understanding of type-II heterojunctions was achieved, and providing valuable insights into the behavior of this specific heterojunction system.

An outstanding photocatalytic performance of CNTs based nanocomposite of ternary metal oxides towards cationic and anionic dyes and pharmaceutical drug

Currently, hetero-metallic oxides and their nanocomposites with 1D materials have a tremendous role in photocatalytic applications, mainly for the removal of organic effluents, due to their higher potential of electron-hole pair migration and separation than pure metal oxide NPs. The present work reports the fabrication of ternary metal oxides nanostructure (WO3·Ag2O·CuO) and its nanocomposite with carbon nanotubes (WO3·Ag2O·CuO/CNTs) using a facile approach i.e. ultra-sonication. The photocatalytic removal efficacy of fabricated nanocomposite i.e. WO3.Ag2O.CuO/CNTs along its counterpart (WO3·Ag2O·CuO) was evaluated using a model cationic dye (Methylene blue, MB), an anionic dye (Congo red, CR), and an analgesic drug (Paracetamol). The catalytic experiment was performed under natural sunlight upon light irradiation of about 90 min and using 30 mg of photocatalyst for all chosen effluents. The obtained results deduced that WO3·Ag2O·CuO/CNTs nanocomposite showed catalytic efficiency of about 97 % for MB, 87 % for CR, and 93 % for Paracetamol while it was about 80 % for MB, 74 % for CR, and 79 % for drug using WO3·Ag2O·CuO as photocatalyst. The rate constant values of nanocomposite for the removal of MB, CR, and Paracetamol are 0.037 min−1, 0.023 min−1, and 0.027 min−1 respectively. The remarkable degradation performance of WO3·Ag2O·CuO/CNTs nanocomposite as compared to ternary metal oxide (WO3·Ag2O·CuO) was due to its high charge separation, high surface area, and availability of large number of active sites for the adsorption of pollutant molecules. Hence, WO3·Ag2O·CuO/CNTs nanocomposite could be a competent photocatalyst for the removal of variety of industrial effluents i.e. organic dyes and pharmaceutical drugs etc.

Sensitizer created defective metal organic framework as a new platform for boosting visible-light photocatalysis of g-C3N4

We developed herein for the first time a sensitizer created defective MOF (SCD-MOF), simultaneously possessing sensitizers and defects as visible-light harvester and electron trapper, respectively, which can synergistically improve the visible-light photocatalysis of polymeric graphitic carbon nitride (g-C3N4). Based on this discovery, the resulting 5.0 wt% FeTCPP⊂UiO-66@g-C3N4 shows a significant 6.6 and 3.9 times improvement in catalytic efficiency compared with its parent materials of FeTCPP⊂UiO-66 and g-C3N4 in degrading organic pollutants. Moreover, it shows a 10.4 times enhancement in catalytic efficiency compared with commercial TiO2 (P25). Mechanism studies suggest that sensitizer molecules and defects in SCD-MOF can synergistically improve photocatalytic efficiency because of broadening the visible-light response and strengthening the charge carrier separation. This work illustrates a remarkably triple synergetic effect among visible-light harvester, electron/hole separator, and semiconductor and thus established SCD-MOF as a class of new platform to greatly improve the visible-light photocatalytic performance of conventional semiconductors.

From waste to treasure: Synthesis of Ag3PO4/TiO2/r-SiC composite photocatalysts with efficient photocatalytic performance using waste photovoltaic silicon wafers

The conversion of low-value waste into high-value-added photocatalysts for pollution removal is considered a promising approach for waste utilization. In this work, regenerated SiC (r-SiC) nanowires were synthesized using waste photovoltaic silicon wafers through a mechanochemical-carbothermal reduction method. The prepared filamentary structure of r-SiC nanowires as a substrate for an Ag3PO4/TiO2/r-SiC (APO/TIO/r-SiC) ternary photocatalyst was prepared by immobilizing TiO2 and Ag3PO4 on r-SiC nanowires. The 30%APO/TIO/r-SiC (loaded with 30 wt%Ag3PO4) achieved more than 90% degradation rate for six organic dyes, and 80% for tetracycline (TC) within 15 min, respectively. The loading of TiO2 and Ag3PO4 improved the adsorption of molecular oxygen in the aqueous environment, which facilitated the generation of reactive oxygen species and enhanced the photocatalytic performance of 30%APO/TIO/r-SiC. The Z and II dual-scheme electron transfer mechanism for 30%APO/TIO/r-SiC was demonstrated to promote effectively carrier separation. Three potential pathways of RhB degradation were proposed, and the disruption of the conjugated structure (chromophore) was the main cause of RhB degradation. The radical quenching experiments revealed that the degradation process was more significantly influenced by •O2- and •OH than h+. The research proposed a promising 'win-win' treatment approach for waste photovoltaic wafers and delved into the photocatalytic performance and enhancement mechanism of SiC-based composite catalysts.

Outstanding photocatalytic degradation performance under low light intensity via mitigating the quenching reaction of oxygen-centered organic radicals and oxygen

Traditional indiscriminate free radicals pose challenges to photocatalyst stability. To address this issue, oxygen-centered organic radicals (OCORs) anchored on catalyst surfaces were developed recently. However, strategies to alleviate the quenching reaction between OCORs and oxygen are lacking. Herein, the tetrasubstituted carbazole derivative-anthraquinone CZAQ-1, generating OCORs, was fabricated as photocatalyst. CzAQ-1 outperforms reported photocatalysts under low-intensity visible light, achieving 100 % degradation efficiency within 90 minutes at 10 mW·cm−2 and 30 minutes at 100 mW·cm−2. It exhibits exceptional stability over 10 cycles and yields hydrogen peroxide production of 3582 μmol·h−1·g−1 during degradation. The outstanding performance is attributed to OCORs serving as the primary oxidative active species, effectively mitigating quenching reactions with oxygen. This process is accomplished through an innovative strategy of reducing the electrostatic potential of oxygen atoms in OCORs. This study provides insights into OCORs and proposes strategies for optimizing organic polymer structures to enhance photocatalytic performance by inhibiting OCORs-oxygen reactions.