Photoelectrochemical Research Articles

The need for robust model systems in the study of hybrid interfaces for photocatalysis and photoelectrocatalysis.

Small molecule conversion to value-added products using renewable energy sources has emerged as a promising strategy to mitigate our reliance on fossil fuels. Hybrid materials that integrate the strengths of photoabsorbers and co-catalysts (electrocatalysts) are essential for maximizing the efficiency of photochemical (PC) and photoelectrochemical (PEC) systems. In this perspective, we will focus on the need for fundamental studies with a strong emphasis on the importance of beginning with well-defined hybrid interfaces. A particular focus is given to small molecule adsorption studies that correlate surface structure and chemistry to reactivity, highlighting its potential in characterizing complex interfaces. We also make the case for understanding how light and electrochemical environments influence surface structure, adsorption, and reactivity and should be considered in model hybrid system design. Finally, we provide a framework to connect the theory and experiment of model hybrid surfaces to provide a molecular understanding of PC and PEC at these interfaces and accelerate our integration of these materials into real systems capable of meeting our renewable energy needs.

Plasmonic Graphene-Gold Nanostar Heterojunction for Red-Light Photoelectrochemical Immunosensing of C-Reactive Protein.

The development of red-light photoelectrochemical (PEC) nanoimmunosensors offers new avenues for detecting clinically relevant biomarkers with high sensitivity and specificity. Herein, the first PEC nanoimmunosensor based on a plasmonic graphene and gold nanostar (AuNS) heterojunction excited with 765 nm red light is presented for label-free detection of C-reactive protein (CRP), a key biomarker of inflammation. This platform leverages the unique localized surface plasmon resonance effect of AuNSs in combination with in situ generated graphene to enhance photoelectrical conversion efficiency under 765 nm monochromatic light. This wavelength minimizes photodamage and interference from biological samples. By optimizing the nanoarchitecture and utilizing a bifunctional photoactive transduction platform, a linear detection range of 25-800 pg/mL is achieved, with a limit of detection as low as 13.3 pg/mL. The low-energy red-light activation, effective electron-hole pair separation, and signal amplification allow CRP's rapid, selective, and sensitive detection in real clinical samples from patients with low-grade chronic inflammation. The nanoimmunosensor demonstrated consistent analytical performance across multiple samples, showing potential for accurate biomarker monitoring in inflammatory disorders. This work highlights plasmonic nanomaterials to develop robust PEC immunosensors that provide scalable, noninvasive, automated, low-background noise as a highly sensitive alternative for clinical diagnostics.

Constructing Photoactive Au NP/MXene–BiOCl Moiré Superlattice Nanosheets for Photoelectrochemical Detection of Protein Kinase Activity

A novel photoelectrochemical (PEC) biosensor was proposed by preparing Au NP/MXene–BiOCl Moiré superlattice nanosheets as the probes. Upon irradiation with visible light, the probe exhibited excellent electrical conductivity as well as high photoelectric conversion efficiency. Benefitting from the excellent PEC property of the hybrid probe, sensitive and accurate detection of protein kinase activity was demonstrated with a limit of detection of 0.0029 U mL−1. This study verifies the great PEC potential of MXene hybrid nanomaterials.

New anchovy burgers: a sustainable and nutritious alternative to red meat in fast food

Abstract This study presents an innovative anchovy burger formulation optimized using response surface methodology and Ideal Profile method. The objective is to create a nutritious, appealing, and environmentally friendly alternative to traditional red meat burgers. The research utilized a two-tiered experimental approach: an initial screening using Plackett-Burman Design to evaluate the impact of various ingredients on cooking yield, texture, and moisture retention, followed by an optimization phase employing a Central Composite Design. Key findings revealed that oat fiber and potato flakes significantly enhance the burger’s cooking yield and sensory characteristics. The optimized formulation, comprising 4% oat fibers and 4% potato flakes, exhibited superior texture and consumer preference. Nutritional analysis demonstrates that the optimized anchovy burger outperforms conventional beef and popular fast food chain burgers in terms of protein content and dietary fibers, while also being a rich source of long-chain polyunsaturated fatty acids. This research contributes to the fast-food industry by offering a product that meets sensory and nutritional requirements while also promoting sustainability. The findings lay a foundation for future studies to further explore the interplay of sensory attributes and consumer preferences, potentially guiding the development of innovative and sustainable fast-food products. Graphical Abstract

Continuous-Flow Synthesis of BiVO4 Nanoparticles: From laboratory scale to practical systems.

Cost-effective and efficient photoelectrochemical (PEC) water splitting stands out as one of the most promising strategies to address sustainable energy supply in the form of green H2. Large-area photoelectrodes featuring precise chemical and morphological control are key components for a practical solar-to-hydrogen conversion. Herein, we report the continuous flow synthesis of BiVO4 nanoparticles (NPs) by using a simple microreactor configuration. The solution containing the as-prepared NPs enables the deposition of BiVO4 photoanodes with areas up to 52 cm2 through a simple and scalable chemical bath deposition method. On the other hand, surface protection by an ultrathin Al2O3 overlayer grown by atomic layer deposition (ALD) increases the performance of the 1 cm2 BiVO4 photoanodes ~ 30%, exhibiting a photocurrent density of ~2.0 mA·cm-2 at 1.23 V vs. the Reversible Hydrogen Electrode in the presence of a sacrificial hole scavenger. The optimized continuous flow synthesis provides an affordable methodology for the fabrication of cost-effective, large-scale photoanodes, which could potentially be applied for different photoelectrochemical reactions.

Batryticatus bombyx improved atopic dermatitis in NC/Nga mice and impact on inflammation and recovery of skin barrier via STAT1/P38/NF-κB downregulation and HO-1/Nrf2 activation in HaCaT keratinocytes.

Batryticatus bombyx (BB) (Beauveria bassiana Vuill.) is used as an herbal medicine and food additive. Although BB has neuroprotective and anti-apoptotic effects, its impacts on atopic dermatitis (AD) are unknown. We evaluated the effects of BB in an NC/Nga mouse model of house dust mite (HDM)-induced AD, in TNF-α and IFN-γ (TI)-stimulated HaCaT keratinocytes, and in a 3D human skin model. NC/Nga mice were induced with HDM and treated with BB for 6 weeks. We assessed skin symptoms, serum levels of IgE, histamine, and IL-6, immune cell counts, and performed histological analysis of dorsal skin tissue. Additionally, we induced inflammation in HaCaT cells and a 3D human skin model using TNF-α/IFN-γ. We measured inflammatory cytokine levels, skin hydration factors, and delved into underlying mechanisms via ELISA, real-time PCR, and Western blot. BB improved skin lesions, reduced thickness, and inflammatory cell infiltration in HDM-induced mice. It alleviated scratching, improved moisture retention, and reduced IgE, histamine, and IL-6 levels. In HaCaT cells, BB inhibited thymic stromal lymphopoietin and increased hyaluronan content. It also upregulated aquaporin-3, hyaluronan synthase-1/3, filaggrin, involucrin, and occludin, enhancing skin hydration and tight junction stability. BB decreased STAT1, p38 MAPK, and NF-κB p65 levels in HaCaT cells and exhibited antioxidant effects by increasing HO-1/Nrf2 expression. BB may serve as a therapeutic alternative for AD treatment by inhibiting skin inflammation.

A Coordination Polymer Gel as Dual Electrode Material: Photoelectrochemical Water Oxidation Coupled Dark CO2 Reduction to Ethanol

AbstractDeveloping photoelectrochemical catalysts to convert CO2 into chemical feedstocks presents a promising approach for clean energy storage by harnessing solar energy. This study examines the potential of a Zn‐based coordination polymer gel (CPG), incorporating terpyridine (TPY) and tetrathiafulvalene (TTF) moieties (Zn‐TPY‐TTF CPG), for artificial photosynthesis. In this novel approach, Zn‐TPY‐TTF CPG serves as both photoanode and dark cathode material in a photoelectrochemical (PEC) cell. When combined with BiVO₄ (BVO) nanostructures to fabricate a heterojunction photoanode, Zn‐TPY‐TTF CPG significantly enhances PEC water‐oxidation, delivering a fourfold increase in photocurrent density at 0.6 V versus Ag/AgCl compared to pristine BVO. Kelvin Probe Force Microscopy (KPFM) confirms improved carrier separation and transport due to favorable band alignment between BVO and Zn‐TPY‐TTF CPG. PEC CO₂ reduction experiments in an H‐cell demonstrate a remarkable 43% Faradaic efficiency for ethanol production at 1.4 V versus Ag/AgCl. The simultaneous water‐oxidation and CO₂ reduction capabilities of Zn‐TPY‐TTF CPG position it as a highly promising candidate for solar energy conversion. Operando FTIR and Raman spectroscopy reveal crucial reaction intermediates, while Density Functional Theory (DFT) calculations provide deeper insights into ethanol formation. This study highlights the potential of Zn‐TPY‐TTF CPG‐based PEC cells to mimic natural photosynthesis and produce valuable chemical products.

Perovskite-driven solar C2 hydrocarbon synthesis from CO2

Abstract Photoelectrochemistry (PEC) presents a direct pathway to solar fuel synthesis by integrating light absorption and catalysis into compact electrodes. Yet, PEC hydrocarbon production remains elusive due to high catalytic overpotentials and insufficient semiconductor photovoltage. Here we demonstrate ethane and ethylene synthesis by interfacing lead halide perovskite photoabsorbers with suitable copper nanoflower electrocatalysts. The resulting perovskite photocathodes attain a 9.8% Faradaic yield towards C2 hydrocarbon production at 0 V against the reversible hydrogen electrode. The catalyst and perovskite geometric surface areas strongly influence C2 photocathode selectivity, which indicates a role of local current density in product distribution. The thermodynamic limitations of water oxidation are overcome by coupling the photocathodes to Si nanowire photoanodes for glycerol oxidation. These unassisted perovskite–silicon PEC devices attain partial C2 hydrocarbon photocurrent densities of 155 µA cm−2, 200-fold higher than conventional perovskite–BiVO4 artificial leaves for water and CO2 splitting. These insights establish perovskite semiconductors as a versatile platform towards PEC multicarbon synthesis.

The Impact of Composition on the Photoelectrochemical Performance of Molybdenum-Modified Tungsten Oxide in Acidic Media

Abstract The efficiency of photoelectrochemical (PEC) water splitting is considerably controlled by the recombination of photogenerated electron/hole charge carriers at the interface. Herein, the correlation between composition and photoelectrochemical activity is studied by utilizing molybdenum-modified tungsten oxide electrodes. Molybdenum tungsten mixed oxides (Mo x W1−x O3) were synthesized by spray-freeze/freeze-drying approach by varying x from 0 to 1 and studied as a photoanode. The structural changes after Mo substitution in tungsten oxide (Mo x W1−x O3; 0 ≤ x ≤ 1.0) were observed as a function of the composition. In binary oxides, monoclinic structure (ℽ-phase) was observed until Mo substitution (x) reached 0.2. A coexistence of both monoclinic and orthorhombic phases was observed for x varying from 0.2 to 0.8. All synthesized n-semiconducting materials were photoelectrochemically active in water splitting under the acidic condition of HClO4. The highest PEC activity was observed for the sample with low Mo content (x = 0.05) for which the narrowest band gap was determined. The overall activity decrease encountered for Mo-rich materials can be related to a higher tendency to photoinduced proton insertion facilitated by rhombohedral structure. The insight into the mechanism was determined by differential electrochemical mass spectrometry (DEMS). Oxygen (m/z 32) and hydrogen peroxide (m/z 34) were identified as main products. The material with small variation in compositions (x = 0.05) significantly influenced catalytic activity and selectivity, highlighting the importance of the material’s design. Graphical Abstract

Nano-Structured InGaN Photoanode for Hydrogen Production Using Photoelectrochemical Water Splitting: A Simulation Study

Abstract InGaN nanostructures have emerged as a promising solution for developing efficient and stable photoelectrodes for hydrogen production using photoelectrochemical (PEC) water splitting. In this work, we investigate the performance of an InGaN nanopyramid photoanode through electrical and optical simulations. The simulated structure consists of a p-GaN/InGaN NP /n-GaN nanopyramid with 12 pairs of TiO2/SiO2 dielectric Bragg reflector. We obtain a short-circuit current and a power density of 12.23 mA/cm2 and 16 mW/cm2, respectively. We also compare the photoelectrochemical properties of the InGaN nanopyramid photoanode and a planar InGaN photoanode. The incident photon conversion efficiency of the InGaN nanopyramid reaches 43% compared to 9.5% in the case of planar InGaN photoanode. The hydrogen evolution rate of the InGaN NP reaches 228 µmol.cm-2.h-1, which is four times higher than the planar InGaN photoanode. As for solar-to-hydrogen efficiency, we obtained 15% and 3% for InGaN nanopyramid and planar InGaN photoanode, respectively. Our results suggest that InGaN nanopyramids can serve as an efficient photoanode to produce hydrogen gas via PEC water splitting.

Effects of Straw Decomposition on Soil Surface Evaporation Resistance and Evaporation Simulation

As a prominent agricultural country, China has widely implemented returning straw to the field in agricultural production. However, as the decomposition of straw progresses, the physical properties of the soil change, inevitably leading to alterations in the soil surface evaporation model. This study investigated the variations in soil evaporation rate, soil moisture content over 60 days after returning straw to the field, and bare soil through two leaching pond experiments. Through soil moisture retention curves at different degrees of decomposition, this study analyzed the impact of straw decomposition on soil’s water retention capacity. Based on measured data, this study formulated models for the soil surface evaporation resistance of bare soil and varying degrees of straw decomposition. With the comparison and contrast between the models, this study clarified the impact of straw decomposition on soil surface evaporation resistance. The main conclusions are the following: The moisture content of the surface soil decreases exponentially over time and, after 40 days of straw decomposition, the water content of the soil under decomposition is higher than that of bare soil. As the moisture content decreases, the cumulative evaporation from the soil increases linearly. The cumulative evaporation of the decomposed straw soil is lower than that of bare soil, with a relative reduction ranging from 3.08% to 32.2%. The straw decomposition significantly enhances the water retention capacity of the soil in the medium-to-high suction range. The straw decomposition enhances the evaporation resistance of the soil surface, and the greater the degree of decomposition, the more significant the enhancement effect. The research findings not only provide a scientific basis for agricultural water management, but also possess practical implications for guiding farmers to adopt more effective moisture retention measures.

Visible light-responsive enrofloxacin PEC aptasensor based on CN QDs sensitized Bi4O5Br2 nanosheets.

The excessive application of enrofloxacin (ENR) results in residues contaminating both food and the environment. Consequently, developing robust analytical methods for the selective detection of ENR is crucial. The photoelectrochemical (PEC) sensor has emerged as a highly sensitive analytical technique that has seen rapid development in recent years. The functioning of a PEC sensor relies on the reducing capacity of photogenerated electrons and the oxidizing capacity of photogenerated holes produced by the photoactive material. Bi4O5Br2 demonstrates its potential in electrochemical detection, but faces inherent challenges, including swift electron-hole recombination and slow carrier migration, which hinder its catalytic activity. In this study, we synthesized carbon nitride quantum dots doped with Bi4O5Br2 (CN QDs/Bi4O5Br2) through an in situ growth method, utilizing this composite as a photoactive material. The incorporation of CN QDs leads to a 17-fold increase in photocurrent compared to Bi4O5Br2 alone. This enhancement is attributed not only to the improved separation of electron-hole pairs, facilitated by the CN QDs, which boosts photocatalytic activity, but also to the enlarged range of visible light absorption. We employed an ENR-specific aptamer as the recognition element, resulting in the construction of a high-performance photoelectrochemical aptasensor for ENR detection. The sensor exhibited a linear detection range of 1×10-1 to 1×106ngmL-1 and a detection limit of 0.033ngmL-1. The impressive performance of the CN QDs/Bi4O5Br2 sensing platform demonstrates its potential application in detecting ENR concentrations in food, biomedical contexts, and environmental analyses. Benefiting from the sensitization of CN QDs, CN QDs/Bi4O5Br2 exhibited 17-fold PEC signal of pure Bi4O5Br2. The presence of quantum dots in CN QDs/Bi4O5Br2 facilitates rapid separation of electron-hole pairs, leading to significantly enhanced PEC activity and improved detection performance for ENR. This research convincingly illustrates that integrating CN QDs with Bi4O5Br2 nanosheets could pave the way for designing more efficient bismuth-based semiconductor photoactive materials for sensing applications.

Solutal Marangoni effect influencing bubble dynamics with varied electrolyte compositions

In the photoelectrochemical (PEC) water splitting system, the intricate interplay between bubble evolution and charge transfer at the electrode-electrolyte interface underscores the paramount importance of studying electrolyte properties. In this paper, the bubble dynamics and gas-liquid interface mass transfer on TiO2 nanorod and nanotube film electrodes are investigated by changing the cation types (K+, Na+, Li+) and concentrations (0.1 M-1.5 M) in alkaline electrolytes. The results indicate that the photocurrent and gas production follow the order of K+ > Na+ > Li+ under the same concentration, which is affected by the solvation of metal cations in aqueous solution and the adsorption on the photoanode surface. Compared with the nanotube electrode, the nanorod electrode enables the bubble to detach at a smaller size and faster rate. The trend of bubble detachment diameter variation with concentration in different cation electrolytes is the same, and follows the order of K+ > Na+ > Li+, which indicates that the force caused by Marangoni effect shows similar rules. The results reveal that the surface tension variation rate induced by ion concentration gradient varies significantly under different cation concentrations, while the variation rate driven by temperature gradient remains notably stable. This confirms that the bubble growth and detachment depend on the solutal Marangoni effect caused by the surface tension variation rate of different alkaline electrolytes with concentration. Therefore, the suitable choice of electrolyte composition is pivotal for regulating the bubble evolution at the electrode-electrolyte interface and improving the PEC system efficiency.

Self-powered photoelectrochemical sensor based on molecularly imprinted polymer-coupled CBFO photocathode and Ag2S/SnS2 photoanode for ultrasensitive dimethoate sensing.

Dimethoate (DIM) is one of the most extensively applied organophosphorus pesticides (OPs), which is used to boost farm productivity due to its high insecticidal efficacy. However, the excessive use of DIM can result in the extensive contamination of soil, groundwater and food. Monitoring of DIM in environmental and food samples is crucial in view of its potential health risks and environmental hazards from excessive residues. The expensive equipment and complex operations for current detection methods greatly limit their practical applications. Herein, a self-powered photoelectrochemical (PEC) sensing platform based on Ag2S/SnS2 photoanode, iron-doped cobalt borate (CBFO) photocathode, and molecularly imprinted polymers (MIPs) was proposed for the detection of DIM. The molecularly imprinted polymers at CBFO photocathode endow the self-powered PEC sensor with high selectivity. The Ag2S/SnS2 photoanode enhances the efficient of electron transfer between the photoanode and photocathode, contributing to the high sensitivity of PEC sensor. The self-powered molecularly imprinted PEC sensor exhibits outstanding sensitivity and selectivity for DIM at concentrations from 1×10-2 to 1×105nM with a detection limit of 5.9 pM. Excellent recoveries (95.4±2.6%, 98.4±2.3%, 106.3±3.3%) were achieved in spiked crown pear samples, indicating that the molecularly imprinted PEC sensor is capable of detecting DIM in real samples. This research provides a novel simple, fast, highly selective and sensitive self-powered molecularly imprinted photoelectrochemical sensing platform for detection of DIM. The fabricated PEC sensor offers a promising candidate for the detection method of organophosphorus pesticides residues, which is of great significance for the fields of food safety and environmental protection.

Surface Nd Sites Boost Charge Transfer of Fe2O3 Photoanodes for Enhanced Solar Water Oxidation.

Photoelectrochemical (PEC) water splitting for hydrogen production is a promising technology for sustainable energy generation. In this work, we introduce Nd sites boost the PEC performance of Fe2O3 photoanodes through a precise gas-phase cation exchange process, which substitutes surface Fe atoms with Nd. The incorporation of Nd significantly enhances charge transfer properties, increases carrier concentration, and reduces internal resistance, leading to a substantial increase in photocurrent density from 0.44 to 0.92 mA cm-2 at 1.23 VRHE. Further enhancement of catalytic activity was achieved by depositing a NiCo(OH)x layer and a photocurrent density of 1.15 mA cm-2 at 1.23 VRHE were obtained. Theoretical calculations corroborate these experimental results, revealing that Nd doping narrows the bandgap, improves charge separation efficiency, and lowers the reaction potential barrier, thereby accelerating water oxidation kinetics. These findings underscore the effectiveness of surface cation exchange and targeted metallic element doping in overcoming the intrinsic limitations of Fe2O3, providing a viable pathway for developing high-performance PEC systems for efficient hydrogen production.

Deprotonation-Constructed Instant Gelation Coating for Staphylococcus Disinfection and Preservation of Fresh Food in Multiple Scenarios.

The ancient proverb "disease enters through the mouth" elucidates the connection between food and pathogens, underscoring the pivotal role of food preservation in preventing foodborne diseases. Drawing inspiration from ancient food preservation techniques such as waxing and the use of spices, a novel approach combining the deprotonation-induced solid-liquid phase separation of natural polymer solutions with the solubilization of plant-derived antibacterial compounds has been developed. The "two-step soaking" construction strategy enables the creation of biodegradable and adaptable for hydrogel coatings with micro-scale thickness. These multifunctional coatings can be applied to the surfaces of fresh fruits, vegetables, and meats in 35 s, providing both moisture retention and antioxidant protection. The coating's versatility allows for the targeted can achieve the elimination of various Staphylococcus and other bacterial strains through the selection of bactericides with differing antibacterial mechanisms. The scalability of this approach offers significant potential for broad applications in sterilization and food preservation in across diverse contexts.

CRISPR/Cas13a-Programmed Cu NCs and Z-Scheme T-COF/Ag2S for Photoelectrochemical Biosensing of circRNA.

Circular RNAs (circRNAs), as a class of noncoding RNA molecules with a circular structure exhibit high stability and spatiotemporal-specific expression, making them ideal cancer biomarkers for liquid biopsy. Herein, a new photoelectrochemical (PEC) biosensor for a highly sensitive circRNA assay in the whole blood of lung cancer patients was designed based on CRISPR/Cas13a-programmed Cu nanoclusters (Cu NCs) and a Z-scheme covalent organic framework/silver sulfide (T-COF/Ag2S) composite. This Z-scheme T-COF/Ag2S composite accelerates electron transfer and produces an excellent initial photocurrent. When CRISPR/Cas13a precisely targets circRNA, it nonspecifically cleaves the triple-helix molecular structure to release DNA fragments (C'/C"). After the C'/C" opens the DNA hairpin probe (HP) modified on the electrode, hybridization chain reactions are performed to produce abundant AT-rich double-stranded DNA with the addition of H1 and H2 probes. Upon the incubation of Cu2+, Cu NCs are in situ formed via the A-Cu2+-T bonds and can effectively quench the photocurrent of the Z-scheme T-COF/Ag2S due to the energy transfer process. This developed PEC biosensor for the circRNA assay shows a low limit of detection of 0.5 fM, and the reusability of DNA-modified magnetic beads (MB-DNA) reduces the detection cost. Moreover, the PEC biosensor can accurately quantify the circRNA level and distinguish the circRNA expression in whole blood from healthy controls and lung cancer patients, offering strong potential in clinical diagnosis.

Jelly fish, <i>Acromitus flagellates </i>as a Potential Source of Hyaluronic Acid for Cosmetic Applications

Hyaluronic acid (HA) is a valuable bioactive polysaccharide that has numerous applications in the nutricosmetic and cosmetic industries. The tremendous increase of jelly fish in fishing environments has led to a huge global demand for better ways to utilize the organism. The present study investigated the potential for extracting hyaluronic acid from the jelly fish, Acromitus flagellates. The extracted powder was fine, hygroscopic and off-white in colour. The viscosity was measured at different concentrations of 1 mg/ml to 5 mg/ml and at the highest shear rate studied (450 s-1), the maximum viscosity obtained was 1.85cp. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the structure of hyaluronic acid with the presence of disaccharide repeats of D-glucuronic acid (GlcUA) and N-acetylglucosamine (GlcNAc) adjoined alternatively by β-1,3 and β-1,4 glycosidic bonds. The UV-Visible spectroscopic absorption data of the extracted sample showed similar characteristics when compared to the standard. Protein contamination was not observed in the SDS PAGE analysis. The moisture retention ability of the extracted hyaluronic acid, as estimated by in vitro analysis, was better than glycerol up to 4h. Hence, Acromitus flagellates is an ideal candidate for extraction of hyaluronic acid that can be applied in cosmetic and pharmaceutical formulations.

Oxygen Activation Biocatalytic Precipitation Strategy Based on a Bimetallic Single-Atom Catalyst for Photoelectrochemical Biosensing.

The traditional biocatalytic precipitation (BCP) strategy often required the participation of H2O2, but H2O2 had the problem of self-decomposition, which prevented its application in quantitative analysis. This work first found that a bimetallic single-atom catalyst (Co/Zn-N-C SAC) could effectively activate dissolved O2 to produce reactive oxygen species (ROS) due to its superior oxidase (OXD)-like activity. Experimental investigations demonstrated that Co/Zn-N-C SAC preferred to produce highly active hydroxyl radicals (•OH), which oxidized 3-amino-9-ethyl carbazole (AEC) to produce reddish-brown insoluble precipitates. Based on this property, a unique oxygen-activated photoelectrochemical (PEC) biosensor was developed for chloramphenicol (CAP) detection. Cesium platinum bromide nanocrystals (Cs2PtBr6 NCs) were a new type of halide perovskite with lead-free, narrow band gaps, and water-oxygen resistance. Cs2PtBr6 NCs showed excellent cathodal PEC performance without an exogenous coreactant and were first used for PEC detection. As a "proof-of-concept application", Co/Zn-N-C SAC was introduced onto the surface of Cs2PtBr6 NCs by using the CAP dual-aptamer sandwich strategy. Co/Zn-N-C SAC activated dissolved O2 to produce ROS, which oxidized AEC to produce precipitates, quenching the cathodal PEC signal of Cs2PtBr6 NCs for CAP detection. In summary, this work first used SAC to overcome the restriction of the traditional enzymatic BCP strategy requiring H2O2, improved the stability and accuracy of quantitative analysis, and also broadened the application range of coreactant-free perovskite-type PEC biosensors.

Synergistic modification of Cu3V2O8 nanosheeta photoelectrodes with NiFe and NiOx for efficient and ultra‐stable photoelectrochemical water oxidation

AbstractBACKGROUNDThe design and development of environmentally friendly, efficient, and stable photoelectrodes are crucial for advancing photoelectrochemical (PEC) water‐splitting technology.RESULTSIn this study, we report a novel strategy for the preparation of copper vanadate (Cu3V2O8) nanosheet arrays using a low‐temperature solution method. Notably, this is the first instance of directly growing Cu3V2O8 nanosheet arrays on FTO (fluorine‐doped tin oxide) conductive glass. The morphology of the developed nanosheet arrays offers a larger specific surface area and improved bulk charge separation efficiency, which are desirable characteristics for PEC water‐splitting applications. To further enhance the stability and PEC performance of the Cu3V2O8 nanosheets, a synergistic modification strategy was employed. This approach involved the deposition of an NiOx passivation layer and the incorporation of an NiFe co‐catalyst. The synergistic modification strategy significantly improved the PEC performance and stability of the Cu3V2O8 nanosheet arrays. The modified photoelectrode achieved an impressive photocurrent of 0.67 mA cm−2 at 1.23 V versus a reversible hydrogen electrode and demonstrated stability for over 80 h of operation.CONCLUSIONThis work provides a new, low‐cost, and effective strategy for the preparation of efficient and stable photoelectrodes for PEC water splitting, which is a crucial step towards the development of environmentally friendly and sustainable energy technologies. © 2025 Society of Chemical Industry (SCI).