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Low fluorescence under visible light excitation and catalytic activity limit many applications of graphene quantum dots in optical detection, biosensing, catalysis and biomedical. The paper reports design and synthesis of histidine, serine and folic acid-functionalized and boron and iron-doped graphene quantum dot (Fe/B-GQD-HSF). The Fe/B-GQD-HSF shows excellent fluorescence behavior and peroxidase-like activity. Excitation of 330 nm ultraviolet light produces the strongest blue fluorescence and excitation of 480 nm visible light produces the strongest yellow fluorescence. The specific activity reaches 92.67 U g-1, which is higher than that of other graphene quantum dots. The Fe/B-GQD-HSF can catalyze oxidation of 3,3',5,5'-tetramethylbenzidine with H2O2 to form blue compound. Based on this, it was used for colorimetric and fluorescence detection of H2O2. The absorbance at 652 nm linearly increases with the increase of H2O2 concentration between 0.5 and 100 µM with detection limit of 0.43 µM. The fluorescence signal linearly decreases with the increase of H2O2 concentration between 0.05 and 100 µM with detection limit of 0.035 µM. The analytical method has been satisfactorily applied in detection of H2O2 in food. The study also paves one way for design and synthesis of functional graphene quantum dots with ideal fluorescence behavior and catalytic activity.
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Boro , Colorimetria , Ácido Fólico , Grafite , Histidina , Peróxido de Hidrogênio , Ferro , Pontos Quânticos , Serina , Pontos Quânticos/química , Grafite/química , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Colorimetria/métodos , Ácido Fólico/análise , Ácido Fólico/química , Ferro/análise , Ferro/química , Boro/química , Histidina/análise , Histidina/química , Serina/análise , Serina/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Análise de Alimentos/métodos , Peroxidase/química , Peroxidase/metabolismo , CatáliseRESUMO
Foodborne pathogens remain a serious health issue in developed and developing countries. Safeness of food products has been assured for years with culture-based microbiological methods; however, these present several limitations such as turnaround time and extensive hands-on work, which have been typically address taking advantage of DNA-based methods such as real-time PCR (qPCR). These, and other similar techniques, are targeted assays, meaning that they are directed for the specific detection of one specific microbe. Even though reliable, this approach suffers from an important limitation that unless specific assays are design for every single pathogen potentially present, foods may be considered erroneously safe. To address this problem, next-generation sequencing (NGS) can be used as this is a nontargeted method; thus it has the capacity to detect every potential threat present. In this chapter, a protocol for the simultaneous detection and preliminary serotyping of Salmonella enterica serovar Enteritidis, Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Escherichia coli O157:H7 is described.
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Microbiologia de Alimentos , Doenças Transmitidas por Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Listeria monocytogenes , Microbiologia de Alimentos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/diagnóstico , Listeria monocytogenes/isolamento & purificação , Listeria monocytogenes/genética , Escherichia coli O157/isolamento & purificação , Escherichia coli O157/genética , Humanos , Sorotipagem/métodos , DNA Bacteriano/genética , DNA Bacteriano/análise , Salmonella typhimurium/isolamento & purificação , Salmonella typhimurium/genéticaRESUMO
To improve the activity of Co/Al2O3 catalysts in selective catalytic oxidation of ammonia (NH3-SCO), valence state and size of active centers of Al2O3-supported Co catalysts were adjusted by conducting H2 reduction pretreatment. The NH3-SCO activity of the adjusted 2Co/Al2O3 catalyst was substantially improved, outperforming other catalysts with higher Co-loading. Fresh Co/Al2O3 catalysts exhibited multitemperature reduction processes, enabling the control of the valence state of the Co-active centers by adjusting the reduction temperature. Changes in the state of the Co-active centers also led to differences in redox capacity of the catalysts, resulting in different reaction mechanisms for NH3-SCO. However, in situ diffuse reflectance infrared Fourier transform spectra revealed that an excessive O2 activation capacity caused overoxidation of NH3 to NO and NO2. The NH3-SCO activity of the 2Co/Al2O3 catalyst with low redox capacity was successfully increased while controlling and optimizing the N2 selectivity by modulating the active centers via H2 pretreatment, which is a universal method used for enhancing the redox properties of catalysts. Thus, this method has great potential for application in the design of inexpensive and highly active catalysts.
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Óxido de Alumínio , Amônia , Cobalto , Oxirredução , Amônia/química , Catálise , Óxido de Alumínio/química , Cobalto/química , Modelos Químicos , Poluentes Atmosféricos/químicaRESUMO
BACKGROUND: Canadian 24-h movement guidelines recommend that adults achieve 150 min per week of moderate-to-vigorous physical activity (MVPA), 7-9 h of sleep per night and spend no more than 8-h per day sedentary to optimise health and wellbeing. METHOD: Using a cross-sectional survey of 131 family caregivers of adults with intellectual and developmental disabilities, we aimed to (a) determine whether adherence to these guidelines predicts mental wellbeing in family caregivers and (b) explore the relationship between movement behaviours of family caregivers and their loved ones. RESULTS: While MVPA was found to weakly predict wellbeing, sleep and sedentary behaviour did not. The movement behaviours of the family caregivers were not closely related to that of their loved ones. CONCLUSIONS: Fostering physical activity is important to promote the wellbeing of adults with intellectual and developmental disabilities, as well as their family caregivers. Opportunities to be active together may be even more beneficial.
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Cuidadores , Deficiências do Desenvolvimento , Exercício Físico , Deficiência Intelectual , Saúde Mental , Comportamento Sedentário , Sono , Humanos , Masculino , Cuidadores/psicologia , Feminino , Deficiência Intelectual/enfermagem , Adulto , Deficiências do Desenvolvimento/enfermagem , Pessoa de Meia-Idade , Estudos Transversais , Sono/fisiologia , Idoso , Adulto Jovem , Canadá , Família/psicologiaRESUMO
Constructing a photocatalytic in-situ Fenton system (PISFs) is a promising strategy to address the need for continuous hydrogen peroxide (H2O2) addition and the low efficiency of H2O2 activation for hydroxyl radical generation in the traditional Fenton reaction. In this study, we constructed a photocatalytic in-situ Fenton system using anthraquinone-modified carbon nitride (AQ-C3N4) for efficient pollutant degradation. The resultant AQ-C3N4 not only enhanced the production of H2O2 but also increased the generation of hydroxyl radical (·OH). Experimental results demonstrated that, the apparent rate constant for the degradation of 2,4-Dichlorophenol (2,4-DCP) by AQ-C3N4-PISFs was 0.145 min-1, which is 2.74 times higher than that of C3N4 under visible light. Density functional theory (DFT) calculations indicate that AQ modification promotes electron-hole separation while increasing the adsorption energy of O2. Independent gradient model (IGM) analysis based on Hirshfeld Partition revealed that van der Waals interactions between AQ-C3N4 and 2,4-DCP promoted the degradation process. This work provides new ideas to overcome the problems of continuous addition of H2O2 and low utilization of ·OH that exist in conventional Fenton system.
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Gout, marked by the deposition of sodium urate crystals in joints and peripheral tissues, presents a considerable health challenge. Recent research has shown a growing interest in nanozyme-based treatments for gout. However, literature on nanozymes that combine uricase-like (UOX) activity for uric acid (UA) degradation with catalase (CAT)-like activity for H2O2 elimination through a self-cascade reaction is limited. Herein, we discovered that two-dimensional Pd@Ir nanosheets (NSs) exhibit UOX and CAT activities effectively. Notably, we observed a size-dependent effect of Pd@Ir on activation energy during UA degradation, with the larger Pd@Ir NSs demonstrating a lower energy barrier. The 46-nm Pd@Ir had activation energy as low as 35.9 kJ/mol, surpassing the efficiency of natural bacterial uricase and most reported nanozymes. Through a tandem self-cascade reaction of Pd@Ir, UA was effectively degraded via UOX activity, while the byproduct H2O2 was simultaneously eliminated by CAT-like activity. Cell experiments revealed that Pd@Ir protect normal cells from oxidative stress and promote cell proliferation, demonstrating an excellent self-cascade effect. Additionally, Pd@Ir substantially alleviated gout symptoms in monosodium urate-induced acute gout mice without causing toxic effects on biological organs and tissues. This study opens new avenues for using nanozyme-based cascade reaction systems in the treatment of metabolic diseases.
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Gota , Paládio , Urato Oxidase , Ácido Úrico , Gota/tratamento farmacológico , Gota/patologia , Animais , Camundongos , Urato Oxidase/química , Urato Oxidase/metabolismo , Paládio/química , Paládio/farmacologia , Nanoestruturas/química , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Humanos , Tamanho da Partícula , Catalase/metabolismo , Catalase/química , Estresse Oxidativo/efeitos dos fármacos , Propriedades de Superfície , Proliferação de Células/efeitos dos fármacosRESUMO
Electrocatalytic CO2 reduction reaction (CO2RR) is a process in which CO2 is reduced to high-value-added C1 and C2 energy sources, particularly ethylene (C2H4), thereby supporting carbon-neutral recycling with minimal consumption. This makes it a promising technology with significant potential. Nevertheless, the low selectivity for C2H4 remains a significant challenge in practical applications. In this paper, a strategy based on Cu-Sn bimetallic catalysts is proposed to improve the selectivity of electrocatalytic conversion of CO2 to C2H4 over Cu-based catalysts. The experimental results show that the Faradaic efficiency (FE) of C2H4 can reach up to 48.74 %, and the FE of C2 product reaches 60 %, at which time the local current density is 11.99 mA/cm2. Compared with pure Cu catalyst, the FE and local current density of C2H4 increased by 55.27 % and 35.33 %, respectively. Moreover, the FE of C2H4 remained above 40 % after 8 h over Cu10-Sn catalyst. The addition of Sn facilitates the transfer of local electrons from Cu to Sn, stabilizes the *CO intermediate, promotes CC coupling, significantly lowers the reaction energy barrier, and enables highly efficient CO2RR catalysis for C2H4 production.
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Co-based bimetallic zeolite imidazolate frameworks (ZIFs) have been shown as promising electrocatalysts for the oxygen evolution reaction, but their electronic structure's influence on the catalytic performance for overall water splitting still needs further investigation. In this study, Co15V-ZIF, structured as two-dimensional (2D) nanosheet arrays, are grown on nickel foam using one-step co-precipitation strategy. Owing to the synergistic effects of vanadium (V) and cobalt (Co) reasonably regulating the electronic structure, the synthesized bimetallic ZIFs demonstrate superior catalytic performance, which required the overpotentials of only 227 and 68 mV to achieve a current density of 10 mA cm-2 in 1 M KOH for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Furthermore, the water electrolyzer assembled with bimetallic ZIF as cathode and anode exhibits the capability to achieve 10 mA cm-2 at a low cell voltage of 1.57 V. In situ Raman spectroscopy reveals that the introduction of V facilitates the formation of V-CoOOH, the real active site for OER, at lower applied potentials. Besides, it induces a local acidic environment on V-Co(OH)2, the real active sites, thereby enhancing the HER performance of the sample. Density Functional Theory (DFT) calculations further show that the synergistic effects of V and Co induce electron redistribution, thereby improving electrical conductivity, reducing the energy barrier for water dissociation and hydrogen adsorption, which promotes the formation of H3O+ and triggering H3O+-induced water reduction in alkaline media. This work provides new insight into tailoring electronic structures to rationally design highly efficient ZIF electrocatalysts.
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Covalent organic frameworks (COFs) have shown great potential in the photocatalytic production of hydrogen peroxide (H2O2) due to their precisely designed and customized ability. Nevertheless, the quest for efficient overall photosynthesis of H2O2 in pure water without sacrificial agents using COF photocatalysts remains a formidable challenge. Herein, three pyrene-based covalent organic frameworks are synthesized using an advanced interfacial design strategy. By incorporating functional groups of F, H, and OH into a COF skeleton, their wettability and charge-separation properties are fine-tuned. These COFs show great performances as photocatalysts for H2O2 production from water and air by utilizing both the oxygen reduction reaction and water oxidation reaction pathways. Compared to PyCOF-F and PyCOF-H, PyCOF-OH demonstrates superior H2O2 production efficiency due to its improved hydrophilicity and enhanced carrier separation, achieving a remarkable rate of 2961 µmol g-1 h-1 from 25 mL pure water and air. Further, the mechanism of H2O2 production over PyCOF-OH is clarified by combining a series of control experiments, in situ characterizations, and theoretical calculations. This study offers valuable insights into the interfacial design of high-performance photocatalysts for H2O2 synthesis.
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Simultaneous optimization of the number and intensity of oxygen (O2) adsorption on gold (Au) cocatalyst is highly required to greatly improve their interfacial hydrogen peroxide (H2O2)-production activity. However, it is a great challenge to realize the above effective modulation of Au by traditional photodeposition route. In this study, a platinum (Pt)-induced selective photodeposition method was designed to simultaneously regulate the particle size and electronic structure of Au cocatalyst for boosting the photocatalytic H2O2-production activity of bismuth vanadate (BiVO4) via the selective deposition of Pt@Au core-shell cocatalyst. The photocatalytic results indicate that the as-prepared BiVO4/Pt0.1@Au photocatalyst achieves a considerable H2O2-production activity with a rate of 2752.13 µmol L-1 (AQE = 13.76 %), which is obviously higher than that of BiVO4/Pt (137.63 µmol L-1) and BiVO4/Au (475.33 µmol L-1). It was found that the introduction of Pt successfully induced the formation of Au nanoparticles for enhancing the number of O2 adsorption. Meanwhile, the spontaneous transfer of free electrons of Au to Pt induces the generation of electron-deficient Auδ+ sites, which spontaneously enhances the O2-adsorption intensity for facilitating the 2-electron oxygen reduction reaction (ORR), resulting in efficient H2O2 production. The present strategy may be useful for more comprehensively regulating the intensity and number of O2 adsorption on cocatalysts to facilitate artificial photosynthesis.
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Protein engineering is an established method for tailoring enzymatic reactivity. A commonly used method is directed evolution, where the mutagenesis and natural selection process is mimicked and accelerated in the laboratory. Here, we describe a reliable method for generating saturation mutagenesis libraries by Golden Gate cloning in a broad host range plasmid containing the pBBR1 replicon. The applicability is demonstrated by generating a mutant library of the iron nitrogenase gene cluster (anfHDGK) of Rhodobacter capsulatus, which is subsequently screened for the improved formation of molecular hydrogen.
Assuntos
Clonagem Molecular , Biblioteca Gênica , Plasmídeos , Plasmídeos/genética , Clonagem Molecular/métodos , Rhodobacter capsulatus/genética , Especificidade de Hospedeiro/genética , Mutagênese/genética , Mutagênese Sítio-Dirigida/métodos , Família Multigênica , Evolução Molecular Direcionada/métodosRESUMO
The utilization of a cost-free sacrificial agent is a novel approach to significantly enhance the efficiency of photocatalytic hydrogen (H2) production by water splitting. Wastewater contains various organic pollutants, which have the potential to be used as hole sacrificial agents to promote H2 production. Our studies on different pollutants reveals that not all pollutants can effectively promote H2 production. However, when using the same pollutants, not all photocatalysts achieved a higher H2 evolution rate than pure water. Only when the primary oxidizing active species of the photocatalyst are â¢OH radicals, which are generated by photogenerated holes, and when the pollutants are easily attacked and degraded by â¢OH radicals, can the production of H2 be effectively promoted. It is noteworthy that the porous brookite TiO2 photocatalyst exhibits a significantly higher H2 evolution rate in Reactive Red X-3B and Congo Red, reaching as high as 26.46 mmolâ g-1â h-1 and 32.85 mmolâ g-1 â h-1, respectively, which is 2-3 times greater than that observed in pure water and is 10 times greater than most reported studies. The great significance of this work lies in the potential for efficient H2 production through the utilization of wastewater.
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Suitable H2O and H adsorption on the surface of transition metal chalcogenide cocatalyst is highly required to achieve their excellent alkaline H2-evolution rate. However, the weak adsorption of H2O and H atoms on NiTe surface greatly hinders its alkaline H2-evolution efficiency. Herein, an electron-deficient modulation strategy is proposed to synchronously improve the adsorption of H2O and H atoms on NiTe surface, which can greatly improve the alkaline photocatalytic H2 evolution of TiO2. In this case, highly electronegative oxygen atoms are introduced into the NiTe cocatalysts to induce the formation of electron-deficient Niδ+ and Teδ+ sites in the ultra-small-sized NiO1-xTex nanodots (0.5-2 nm), which can be uniformly loaded onto the TiO2 surface to prepare the NiO1-xTex/TiO2 photocatalysts by a facile complexation-photodeposition strategy. The resulting NiO1-xTex/TiO2 (0.6:0.4) photocatalyst exhibits the optimal activity (2143.36 µmol g-1 h-1), surpassing the activity levels of TiO2 and NiTe/TiO2 samples by 42.3 and 1.8 times, respectively. The experimental and theoretical investigations have revealed that the presence of highly electronegative O atoms in the NiO1-xTex cocatalyst can redistribute the charges of Ni and Te atoms for the formation of electron-deficient Niδ+ and Teδ+ active sites, thereby synchronously enhancing the adsorption of H2O on Niδ+ sites and H on Teδ+ sites and promoting alkaline photocatalytic H2 evolution. The current research about the synchronous optimization of the H2O and H adsorption offers a significant approach to design high-performance H2-evolution materials.
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In this study, a simple one-pot synthesis process is employed to introduce Pd dopant and abundant S vacancies into In2S3 nanosheets. The optimized Pd-doped In2S3 photocatalyst, with abundant S vacancies, demonstrates a significant enhancement in photocatalytic hydrogen evolution. The joint modification of Pd doping and rich S vacancies on the band structure of In2S3 result in an improvement in both the light absorption capacity and proton reduction ability. It is worth noting that photogenerated electrons enriched by S vacancies can rapidly migrate to adjacent Pd atoms through an efficient transfer path constructed by Pd-S bond, effectively suppressing the charge recombination. Consequently, the dual-defective In2S3 shows an efficient photocatalytic H2 production rate of 58.4 ± 2.0 µmol·h-1. Additionally, further work has been conducted on other ternary metal sulfide, ZnIn2S4. Our findings provide a new insight into the development of highly efficient photocatalysts through synergistic defect engineering.
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Utilizing spontaneous polarization field to harness charge transfer kinetics is a promising strategy to boost photocatalytic performance. Herein, a novel Cu atom clusters/PtCu alloy nanocubes coloaded on nitrogen-rich triazole-based C3N5 (PtCu-C3N5) with dipole field was constructed through facile photo-deposition and impregnation method. The dipole field-drive spontaneous polarization in C3N5 acts as a charge-transfer bridge to promote directional electron migration from C3N5 to Cu atom clusters/PtCu alloy. Through the synergistic effects between Cu atom clusters, PtCu alloy and dipole field in C3N5, the optimized Pt2Cu3-C3N5 achieved a record-high performance with H2 formation rate of 4090.4 µmol g-1 h-1 under visible light, about 154.4-fold increase compared with pristine C3N5 (26.5 µmol g-1 h-1). Moreover, the apparent quantum efficiency was up to 25.33 % at 320 nm, which is greatly superior than most previous related-works. The directional charge transfer mechanism was analyzed in detail through various characterizations and DFT calculations. This work offers a novel pathway to construct high-efficiency multi-metal photocatalysts for solar energy conversion.
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Photocatalytic water splitting technology for H2 production represents a promising and sustainable approach to clean energy generation. In this study, a high concentration of oxygen vacancies was introduced into tungsten trioxide (WO3) to create a vacancy-rich layer. This modified WO3 (WO3-x) was then combined with N-doped Zn0.6Cd0.4S through a hydrothermal synthesis, resulting in the formation of a Z-scheme heterojunction composite aimed at enhancing photocatalytic performance. Under visible light, the H2 production activity of the composite reached an impressive 8.52 mmol·g-1 without adding co-catalyst Pt. This corresponds to enhancements of 7.82 and 4.39 times the production yield of pure ZCS and ZCSN, respectively. However, the hydrogen production increased to 21.98 mmol·g-1 when Pt was added as a co-catalyst. Furthermore, an array of characterizations were employed to elucidate the presence of oxygen vacancies and the establishment of the Z-scheme heterojunction. This structural enhancement significantly facilitates the utilization of photo-generated electrons while effectively preventing photo-corrosion of ZCSN, thus improving material stability. Our study provides a new scheme for the incorporation of oxygen-rich vacancy and the construction of Z-scheme heterojunction, demonstrating a synergistic effect that greatly advances photocatalytic performance.
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Piezocatalysis offers an encouraging alternative for the sustainable, on-demand, and decentralized production of hydrogen peroxide (H2O2), underscoring the importance of enhancing piezocatalytic efficiency. Enhancing piezocatalysts through defect engineering has shown considerable potential in boosting H2O2 production efficiency. However, the impact of oxygen vacancies on piezocatalytic activity remains unclear. Herein, we used a chemical probe method to quantify negative charges (q-) and superoxide radicals (O2-) to explore the relation between the oxygen vacancy concentration and piezocatalytic performance of bismuth titanate (Bi4Ti3O12) based catalysts. Results indicate that piezocatalytic H2O2 production in pure water demonstrates a volcanic trend with increasing oxygen vacancy concentration. This trend is attributed to the dual role of oxygen vacancies, which reduce the piezoelectric property of the piezocatalyst while simultaneously increasing the concentration of O2-, which is crucial for H2O2 formation through the O2 reduction pathway. This study provides insights into the interplay between oxygen vacancies, piezoelectric properties, and piezocatalytic activity, offering valuable guidance for the design of piezocatalysts for sustainable H2O2 production.
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To promote the greening and economization of industrial production, the development of advanced catalyst manufacturing technology with high activity and low cost is an indispensable part. In this study, nitrogen-doped hollow carbon spheres (NHCSs) were used as anchors to construct a supramolecular coating formed by the self-assembly of boron clusters and ß-cyclodextrin by surface crystallization strategy, with the help of the weak reducing agent characteristics of boron clusters, highly dispersed ultra-small nano-palladium particles were in-situ embedded on the surface of NHCSs. The deoxygenation hydrogenation of nitroaromatics and the reduction of nitrate to ammonia were used as the representatives of thermal catalytic reduction and electrocatalytic reduction respectively. The excellent properties of the constructed Pd/NHCSs were proved by the probe reaction. In the catalytic hydrogenation of nitroaromatics to aminoaromatics, the reaction kinetic rate and activation energy are at the leading level. At the same time, the constructed Pd/NHCSs can also electrocatalytically reduce nitrate to high value-added ammonia with high activity and selectivity, and the behavior of Pd/NHCSs high selectivity driving nitrate conversion was revealed by density functional theory and in situ attenuated total reflection Fourier transform infrared (ATRFTIR) technique. These results all reflect the feasibility and superiority of in-situ anchoring ultra-small nano-metals as catalysts by surface crystallization to build a supramolecular cladding with reducing properties, which is an effective way to construct high-activity and low-cost advanced catalysts.
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Developing effective photocatalysts to achieve stable and efficient solar-induced hydrogen production remains a significant challenge due to rapid photocarrier recombination and sluggish hydrogen evolution kinetics. Here, a multi-interfacial engineering strategy involving the decoration of metallic Ni3C onto CaTiO3/Mn0.5Cd0.5S was proposed to create an S-scheme/Schottky hybrid heterostructure with multiple carrier transport paths for effective photocatalytic H2 production. Exploiting the synergy between S-scheme heterojunction and Schottky barrier, the engineered ternary CaTiO3/Mn0.5Cd0.5S/Ni3C hybrid heterojunction exhibits outstanding photostability and significantly enhanced hydrogen evolution activity of 79.1 mmol g-1 h-1, which was about 4.55, 3.22 and 2.59 times greater than Mn0.5Cd0.5S, Mn0.5Cd0.5S/Ni3C, and CaTiO3/Mn0.5Cd0.5S, respectively. By creating an S-scheme heterojunction between CaTiO3 and Mn0.5Cd0.5S, accompanied by a robust internal electric field (IEF), spatial charge separation can be effectively accelerated while ensuring the simultaneous preservation of highly active electrons and holes. Meanwhile, Ni3C nanoparticles, acting as a Schottky-junction H2 generation cocatalyst, can efficiently trap the photoinduced electrons to establish multiple charge transfer channels and supply ample active sites for photoreduction reaction, thereby further optimizing the hydrogen generation kinetics. The integration of a Schottky barrier and S-scheme heterojunction in this research is expected to offer new perspectives for designing other highly effective hybrid catalysts for solar-to-hydrogen fuel conversion.
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Combining photocatalytic reduction with organic synthetic oxidation in the same photocatalytic redox system can effectively utilize photoexcited electrons and holes from solar to chemical energy. Here, we stabilized 0D Au clusters on the substrate surface of Zn vacancies modified 2D ZnIn2S4 (ZIS-V) nanosheets by chemically bonding Au-S interaction, forming surfactant functionalized Au/ZIS-V photocatalyst, which can not only synergistic accelerate the selective oxidation of phenylcarbinol to value-added products coupled with clean energy hydrogen production but also further drive photocatalytic CO2-to-CO conversion. An internal electric field of Au/ZIS-V ohmic junction and Zn vacancies synchronously promote the photoexcited charge carrier separation and transfer to optimized active sites for redox reactions. Compared with CO2 reduction in water and the pristine ZnIn2S4, the reaction thermodynamics and kinetics of CO2 reduction over the Au/ZIS-V were simultaneously improved about 11.09 and 45.51 times, respectively. Moreover, the photocatalytic redox mechanisms were also profoundly studied by 13CO2 isotope tracing tests, in situ electron paramagnetic resonance (in situ EPR), in situ X-ray photoelectron spectroscopy (in situ XPS), in situ diffuse reflection infrared Fourier transform spectroscopy (in situ DRIFTS) and density functional theory (DFT) characterizations, etc. These results demonstrate the advantages of vacancies coupled with metal clusters in the synergetic enhancement of photocatalytic redox performance and have great potential applications in a wide range of environments and energy.