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Designing and constructing a robust interaction at photoanode/cocatalyst interface to achieve high activity is a pressing necessity for the advancement of photoelectrochemical water splitting technology. Herein, the modification of BiVO 4 photoanodes with MOF-derived CoZnPO x cocatalysts was successfully achieved through the application of precipitation and low-temperature phosphorylation processes. A high photocurrent density of 3.72 mA/cm2 at 1.23 V (vs. reversible hydrogen electrode (RHE)) was obtained, accompanied by a negative shift in the onset potential (approximately 174 mV). The incorporation of P–O bonds has been demonstrated to result in a redistribution of electron density and the formation of strong electronic interactions between CoZnPO x and BiVO 4 photoanode. These changes have been shown to significantly improve hole mobility, facilitate charge separation and optimize the kinetic processes, thereby enhancing the overall performance of the water oxidation reaction. • A strong electronic interaction between CoZnPO x and BiVO 4 photoanode has been formed. • The strong electronic interaction reduced interfacial kinetic barriers for charge transfer. • The incorporation of P–O bonds reduced the energy barrier of ∗O → ∗OOH during OER. • A high photocurrent density of 3.72 mA/cm2 has been obtained at 1.23 V vs. RHE. [ABSTRACT FROM AUTHOR]

Photoelectrochemical water splitting has emerged as a key technology for harnessing clean and renewable hydrogen energy. Gallium nitride (GaN) has gained attention as a promising material for this purpose due to its strong chemical bonds, resistance to electrolyte corrosion, favorable redox potentials for water reactions, and high carrier mobility facilitating efficient charge transfer. In addition, the bandgap of GaN can be tuned using Indium doping to optimize visible light absorption. Here, we provide a comprehensive review of the methods proposed by our research group and others to enhance the efficiency of GaN-based semiconductors for photoelectrochemical water splitting, with a particular focus on nanostructures, co-catalysts and heterojunctions. This work paves the way for the development of efficient photoelectrochemical water splitting solutions for a sustainable hydrogen future. • Review of the methods to enhance the efficiency of GaN-based semiconductors for photoelectrochemical water splitting. • Review of different heterostructures to facilitate the separation and transfer of photoinduced charges. • Review of different nanostructures to increase the light absorption and the number active sites. • Review of different catalysts to accelerate PEC water splitting reaction rates. [ABSTRACT FROM AUTHOR]

It is of great significance to design photoelectrodes with high carrier separation and transport efficiency in photocatalytic water separation systems. In this study, we used a simple electrochemical deposition method to regulate the load of co‐catalyst CoP on TiO2 nanorods to improve the photoelectrochemical properties. The photocurrent density of TiO2/CoP (20) photoanode at 1.23 V increases to 1.57 mA/cm2, which is 3.4 times that of original TiO2. Long‐term photoelectrolysis reveals that this electrode has excellent stability. Mechanistic studies support the role of CoP nanoparticles in improving photoelectrochemical property and imply that the excellent photoelectrochemical property of TiO2/CoP photoanode is mainly ascribed to the suppress of surface photogenerated electrons and holes recombination due to the construction of built‐in electric field between TiO2 and CoP. [ABSTRACT FROM AUTHOR]

α-Fe 2 O 3 attracted great attention as a promising photoanode candidate for photoelectrochemical (PEC) H 2 O spitting. In this paper, one dimensional (1D) α-Fe 2 O 3 nanorods coupled 2D porous In 2 O 3 nanosheet assemblies were designed to construct a S-scheme α-Fe 2 O 3 /In 2 O 3 heterojunction photoanode. The unique porous In 2 O 3 nanosheet assemblies are conductive to improve light-harvesting efficiency and provide more active sites. An internal electric field induced at the α-Fe 2 O 3 /In 2 O 3 heterojunction interface could promote interfacial charge separation and transfer, enhancing redox kinetics. The as-obtained 2D/1D In 2 O 3 /α-Fe 2 O 3 photoanode achieved a stable photocurrent density of 2.2 mA cm−2 at 1.23 V (vs. RHE). It is 6.3 times higher than that of the α-Fe 2 O 3 component, and got a max applied bias photo-to-current efficiency (ABPE) of 0.28%, which is about 5.8 times that of bare α-Fe 2 O 3 at 1.01 V. The work provides a promising strategy to construct high-performance S-scheme heterostructure photoanodes, featuring the role of surface and interface science in sustainable energy. [Display omitted] • 1D α-Fe 2 O 3 nanorods coupled 3D porous In 2 O 3 nanosheet assemblies were constructed. • In 2 O 3 nanosheets modified on α-Fe 2 O 3 nanorods could promote interfacial charge separation and transfer. • α-Fe 2 O 3 /In 2 O 3 photoanode achieved 2.2 mA cm−2 at 1.23 V (vs. RHE) and ABPE of 0.28% at 1.01 V. • The photoanode follows a S-scheme mechanism for enhanced photoelectrochemical activity. [ABSTRACT FROM AUTHOR]

ZnIn2S4 nanosheets are a promising photoanode for driving photoelectrochemical (PEC) hydrogen fuel production; nevertheless, poor charge separation and sluggish surface reaction kinetics hinder its PEC performance to an extreme degree. Herein, a facile element doping strategy (i.e., P element) was developed to obtain the desired photoanode. As a result, the ZnIn2S4-P (ZIS-P5) photoanode exhibits a remarkable photocurrent density of 1.66 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (VRHE) and a much lower onset potential of 0.12 V vs. RHE for water oxidation. Careful electrochemical analysis confirms that the P doping and sulfur vacancies (Sv) not only facilitate the hole transfer, but also boost surface reaction kinetics. Finally, the "killing two birds with one stone" goal can be achieved. Moreover, the optimized photoanode also presents high PEC performance for urea oxidation, obtaining a photocurrent density of 4.13 mA cm−2 at 1.23 V vs. RHE. This work provides an eco-friendly, simple and effective method to realize highly efficient solar-to-hydrogen conversion. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) organic conversion is a promising approach to convert low‐cost organics to value‐added chemicals, which urgently needs the development of efficient and highly selective photoanodes. Here, a Pt single‐atom dispersed WO3 amorphous/crystalline homojunction for anodic glycerol oxidation reaction (GOR) coupled with cathodic hydrogen generation is reported. In the coupled photoelectrocatalytic system, the novel Pt‐SA/WOx photoanode reaches a photocurrent density of 2.85 mA cm−2 at 1.2 V versus RHE, with up to 297.3 mmol m−2 h−1 of glycerol conversion rate and 60.2% of dihydroxyacetone (DHA) selectivity, realizing green synthesis of high‐value chemicals. The experimental data and theoretical calculations reveal the regulated band structure, build‐in electric field, and surface charge density of Pt‐SA/WOx, which can improve the carrier lifetime, accelerate charge transfer, and reduce the energy barrier for the GOR process, thus boosting PEC activity and DHA selectivity. This work provides a feasible plan for designing atomic‐level engineering and constructing amorphous/crystalline homojunction on photoanodes for efficient PEC high‐value products from biomass. [ABSTRACT FROM AUTHOR]

BiVO 4 photoanode shows severe recombination of photogenerated carriers, which limits its water oxidation performance for photoelectrochemical (PEC) water splitting. In this paper, the surface of BiVO 4 photoanode was modified through the coupling of phosphotungstic acid (H 3 O 40 PW 12 ·xH 2 O, denotes as PWO) with CoOOH to address such drawbacks. At 1.23 V RHE , the photocurrent density of BiVO 4 /PWO/CoOOH photoanode reaches 2.80 mA/cm2, which is 2.59-fold that of bare BiVO 4 photoanode. Moreover, the initial onset potential of BiVO 4 /PWO/CoOOH photoanode is also negatively decreased by 270 mV than that of bare BiVO 4 photoanode. Detailed structural and electrochemical characterizations demonstrate that the decoration of PWO serves as an intermediate layer to promote the transport of holes from BiVO 4 to CoOOH, while the deposition of CoOOH acts as a protective layer as well as cocatalyst to reduce the photocorrosion and improve the PEC activities of BiVO 4. The synergistic coupling of PWO and CoOOH not only makes efficient bulk and surface charge separation, but also takes full advantage of photo-generated holes on the surface, which accelerates water oxidation kinetics, ultimately achieving an improvement in PEC water oxidation. PWO and CoOOH, which widens the range of light absorption and effectively enhances the capacity of light absorption, can therefore induce BiVO 4 to produce more photogenerated charge. Meanwhile, CoOOH facilitates the kinetics of water oxidation. The synergistic effect of PWO and CoOOH improves the PEC performance of BiVO 4. [Display omitted] • BiVO 4 /PWO/CoOOH composite photoanode is reasonably designed and synthesized. • BiVO 4 /PWO/CoOOH photoanode shows excellent stability for PEC. • BiVO 4 /PWO/CoOOH electrode exhibited a high PCD of 2.8 mA/cm2 at 1.23 V RHE. • Synergistic effects of PWO and CoOOH deposition improved the performance. [ABSTRACT FROM AUTHOR]

Constructing high-quality interfaces is critical for improving carrier separation efficiency in heterojunctions. Herein, the WO 3 /CuWO 4 /CuO ternary heterojunction films was constructed on FTO substrates for the first time through in-situ technique as an effective photoanode for photoelectrochemical hydrogen production. The CuO nanoparticles loaded WO 3 nanorod with buffer layer CuWO 4 significantly increased the absorption capability of visible light, accelerate charge separation and enhanced photoelectrochemical performance. The photocurrent density of WO 3 /CuWO 4 /CuO heterojunction photoelectrode achieved 2.24 mA∙cm-2 at 1.23 V vs. RHE, which is nearly 5.6 times higher than bare WO 3 photoanode. In addition, the onset potential of WO 3 /CuWO 4 /CuO heterojunction shifted negatively by 110 mV compared to WO 3. This work indicates that designing high-quality interface heterojunction photoanodes via an atomic shared is an effective strategy for achieve effective photoelectrochemical performance. [Display omitted] • The WO 3 –CuWO 4 –CuO heterojunction photoanode was fabricated by an in situ method. • The photoanode improved light absorption capacity and charge transfer. • The cascaded energy level structure significantly enhanced the PEC performance. • The heterostructure reduced the onset potential and facilitated the evolution of H 2. [ABSTRACT FROM AUTHOR]

Surface-coupled transition metal oxyhydroxide (TMOOH) on semiconductor (SC)-based photoanodes are effective strategies for improving photoelectrochemical (PEC) performance. However, there is a substantial difference between the current density and theoretical value due to the inevitable interfacial charge recombination of SC/TMOOH. Here, we employ BiVO4/FeNiOOH as a model, constructing the BiVO4/MnOx/CoOx/FeNiOOH integrated system by introducing a novel hetero-interface regulation unit, i.e., MnOx/CoOx. As expected, the optimized integrated system demonstrates a photocurrent density as high as 5.0 mA/cm2 at 1.23 V versus the reversible hydrogen electrode (RHE) under 1 sun AM 1.5G illumination, accompanied by 12-h stability. The detailed electrochemical analysis and intensity modulated photocurrent spectroscopy (IMPS) have confirmed that the high PEC performance mainly originates from the hetero-interface structure, which not only suppresses the interfacial charge recombination by accelerating the photogenerated hole transfer kinetics from BiVO4 to FeNiOOH but promotes the kinetics of surface oxygen evolution reaction (OER). Notably, these findings can also be extended to other structures (CeOx/CoOx), reflecting its universality. This finding has provided a new insight into the highly efficient solar energy conversion in the SC/TMOOH system. [ABSTRACT FROM AUTHOR]

Broadband, sensitive, and spectrally distinctive photodetectors show great applications in multifunction optoelectronic devices, which usually integrate multiple photodetectors for distinguishing different spectra. Recently, UV‐induced photocurrent polarity‐switching in individual photoelectrochemical photodetectors (PEC PDs) has been demonstrated by tuning the interfacial physical/chemical processes. However, broadband and spectrally distinctive PEC PDs are still scarce. Here, mosaic t‐Se/InSe heterojunctions are used for designing broadband and spectrally distinctive PEC PDs. Mosaic t‐Se/InSe photoelectrodes are fabricated by one‐step electrochemical deposition with annealing treatment. t‐Se/InSe self‐powered PEC PDs show a broadband photoresponse from UV to near‐infrared (NIR). The photocurrent is negative for UV‐visible spectra and turns positive under NIR irradiation. The light‐induced photocurrent polarity‐switching originates from the competition of different redox reactions at the t‐Se/InSe photoelectrode/electrolyte interface. The responsivity is −22.5, −10.93, −4.18, and 2.48 mA W−1 for 365, 525, 630, and 850 nm light, respectively, exceeding most spectrally distinctive solid‐state PDs. The boosted photoresponse of t‐Se/InSe is attributed to the synergistic effect of stronger light absorption, faster carrier transport, and accelerated interfacial charge transfer. Moreover, the devices show great potential for applications in encrypted optical communications. This work provides a way for designing broadband and spectrally distinctive PEC PDs and demonstrates their potential applications. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BVO) is regarded as an exceptional photoanode material for photoelectrochemical (PEC) water splitting, but it is restricted by the severe photocorrosion and slow water oxidation kinetics. Herein, a synergistic strategy combined with a Co3(HPO4)2(OH)2 (CoPH) cocatalyst and an Al2O3 (ALO) passivation layer was proposed for enhanced PEC performance. The CoPH/ALO/BVO photoanode exhibits an impressive photocurrent density of 4.9 mA cm−2 at 1.23 VRHE and an applied bias photon-to-current efficiency (ABPE) of 1.47% at 0.76 VRHE. This outstanding PEC performance can be ascribed to the suppressed surface charge recombination, facilitated interfacial charge transfer, and accelerated water oxidation kinetics with the introduction of the CoPH cocatalyst and ALO passivation layer. This work provides a novel and synergistic approach to design an efficient and stable photoanode for PEC applications by combining an oxygen evolution cocatalyst and a passivation layer. [ABSTRACT FROM AUTHOR]

The CQDs + Ni(OH) 2 /BiVO 4 photoanode was fabricated by introducing CQDs with fluorescence and optical properties. The CQDs + Ni(OH) 2 /BiVO 4 photoanode exhibited a low water oxidation onset potential (∼0.2 V vs. RHE) and a photocurrent density of 3.05 mA cm−2 at a voltage of 1.23 V vs. RHE, which is about 2.5 times than that of the unmodified BiVO 4 electrode, and the charge injection efficiency is 65%. Surface dynamics test showed that CQDs + Ni(OH) 2 /BiVO 4 photoanode had higher charge transfer rate and lower charge recombination rate than BiVO 4 electrode. As a cheap and stable catalyst for water oxidation, Ni(OH) 2 combined with CQDs can effectively improve the migration of photogenerated electrons and holes, thereby improving the photoelectrochemical (PEC) water oxidation activity of the photoanode. [Display omitted] • Compared with other electrodes, CQDs + Ni(OH) 2 /BiVO 4 showed the largest photocurrent. • The joint effect of CQDs and Ni(OH) 2 enhances the charge injection efficiency. • CQDs and Ni(OH) 2 jointly reduce the surface charge recombination. • Ni(OH) 2 combined CQDs improve the migration of photogenerated electrons and holes. • The stability of CQDs + Ni(OH) 2 /BiVO 4 is far superior to that of other electrodes. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of a novel composite photocatalyst, Co/CoO@Fe2V4O13, is reported by the deposition of CoO metal oxide nanoparticles on the surface of Fe2V4O13 bimetallic oxide. The synthesised photocatalyst exhibited a band gap of roughly 1.8 eV, rendering it responsive to the complete visible light spectrum of the sun, thereby enabling optimal absorption of solar radiation. The Co/CoO@Fe2V4O13 composites demonstrated an enhanced photoelectrochemical water oxidation capacity compared to pristine Fe2V4O13 when exposed to visible light. The enhanced performance is attributed primarily to the creation of a p‐n junction at the interface of Fe2V4O13 and Co/CoO, as well as the Z‐scheme charge transfer mechanism, which aids in the separation and transfer of photogenerated charge carriers. Light absorption by Co nanoparticles via plasmonic excitation and intra‐ and inter‐band transitions in the composite structure is also likely, resulting in increased composite efficiency. Our findings indicate that Co/CoO@Fe2V4O13 composites show promising performance for solar water splitting applications and offer new perspectives for designing effective photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 2 TiO 5 /NiCo-LDH composite photoelectrode exhibits dual role as heterojunction and co-catalyst. • The effect of surface state on charge transfer is systematically discussed. • Fe 2 TiO 5 /NiCo-LDH photoelectrode expands application in photoelectrochemistry for sulfide oxidation reaction. The Fe 2 TiO 5 photoelectrode is limited in photoelectrochemical field (PEC) due to the slow charge transfer kinetics, short carrier diffusion distances and low separation efficiency. Hence, the Fe 2 TiO 5 /NiCo-LDH photoelectrodes with dual roles of co-catalyst and heterojunction are constructed, in which the photogenerated carriers are effectively separated and the conductivity is enhanced. At the same time, the surface state of the Fe 2 TiO 5 -based photoanode is modulated by the co-catalyst, which drives charge transfer into the electrolyte. With the synergistic effect of inhibiting photogenerated carrier complexation and accelerating charge transfer, the OER photocurrent density of Fe 2 TiO 5 /NiCo-LDH photoelectrode is enhanced to 2.42 mA/cm2, which is 3.4 folds higher than that of pristine Fe 2 TiO 5. Specifically, Fe 2 TiO 5 /NiCo-LDH photoanode exhibits good stability and photoelectrochemical performance in hydrogen sulfide oxidation reaction (SOR). Similar to the OER, the sulphur oxidation photocurrent density of Fe 2 TiO 5 /NiCo-LDH photoelectrodes is enhanced to 0.21 mA/cm2, which is 2 folds higher than that of pristine Fe 2 TiO 5. This work provides a new idea for the modification of Fe 2 TiO 5 photoanodes and also explores a pioneering demonstration for the photoelectrochemical decomposition of hydrogen sulfide. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4, BVO) as a promising photoelectrode has been received great attention for photoelectrochemical (PEC) water splitting. However, the slow oxidation kinetics on the surface of BiVO4 limited the PEC water splitting efficiency. Herein, nickel boride (Ni3B, NB) nanoparticles, generally used in electrocatalytic field material, were modified on the surface of BiVO4 photoelectrode as an efficient cocatalyst to accelerate the oxygen evolution reaction. The as-prepared BVO-NB-5P photoelectrode exhibits a remarkable photocurrent density of 1.47 mA·cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE) under air mass (AM) 1.5 G illumination, which is about 2.8 times higher than the bare BiVO4 photoelectrode, and its water splitting rate is 11.3 times higher than bare BiVO4. The PEC studies reveal that the spin coated Ni3B crystal cocatalyst could effectively reduce the water oxidation barrier, and improve the surface charge injection efficiency to 94%, which could boost the photogenerated holes reaction to enhance the PEC performance of BiVO4 photoelectrode. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) splitting water technology over the years has gradually matured, and now photoanodes loaded with nanoparticles (NPs) show excellent PEC performance. Each of the metal NPs has a different effect on the PEC performance of BiVO4. This work selected the noble metals Ag and Au to modify BiVO4 and study its PEC performance. After recombination, the photocurrent densities of Ag/BiVO4 and Au/BiVO4 photoanodes were 3.88 mA/cm2 and 1.61 mA/cm2 at 1.23 VRHE, which were 3.82 and 1.72 times that of pure BiVO4. The hydrogen evolution of pure BiVO4 is about 1.10 μmol·cm−2. Ag/BiVO4 and Au/BiVO4 contain 3.56 and 2.32 times pure BiVO4, respectively. Through the research, it was found that the composite noble metal (NM) NPs could improve the PEC properties; this is because NM NPs can introduce a surface plasmon resonance (SPR) effect to increase the concentration and accelerate the separation of carriers. The mechanism of the SPR effect can be explained as NM NPs are excited by light generating "hot electrons", and the hot electrons can directly enter the conduction band (CB) of BiVO4 through an electron transfer mechanism. The potential energy of the Schottky barrier generated by the contact of NM NPs with BiVO4 is smaller than that generated by the SPR effect, which enables the "hot electrons" to be smoothly transferred from the NM NPs to the conduction band of BiVO4 without returning to the NM NPs. Ag/BiVO4 showed higher PEC activity than Au/BiVO4 because of its higher light absorption, photocurrent, and oxygen evolution capacity. It can be seen that loading NM NPs increases the concentration of the carriers while the separation and transfer rates of the carriers are improved. In conclusion, it was concluded from this study that the loading of NM NPs is an effective method to improve the water oxidation kinetics of BiVO4 photoanodes. [ABSTRACT FROM AUTHOR]

A sandwich-type photoelectrochemical (PEC) immunosensor was constructed on a screen-printed electrode (SPE) using gold-coated tin selenide quantum dots (Au-SnSe QDs) to determine the carbohydrate antigen 19 9 (CA19-9). Water-soluble Au-SnSe QDs were prepared by coating low-cost SnSe QDs, prepared by reacting tin(II) 2-ethyl hexanoate with selenium ions (HNaSe) without needing to add an external capping agent (SnSe QDs). SnSe-based QDs were characterized using high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS). DSP (dithio-bis (succinimidyl propionate)) as a linker was attached on Au@SnSe QDs and conjugated with CA19-9 monoclonal antibodies (Ab2-DSP-Au@SnSE QD). For capture probe assembling, an Au nano-layer was electrochemically deposited on a SPE by HAuCl4 reduction using 12 cycles of cyclic voltammetry (0 to − 1.4 V) at the scan rate of 50 mV s−1, then covered by self-assembly of DSP and covalent conjugation of CA19-9 Ab1. Our developed PEC immunosensor showed a significant photoelectrochemical response, recorded using chronoamperometry (0.3 V), for the presence of CA19-9 antigen in serum samples under light irradiation, with a detection limit (LOD) of 0.0011 U mL−1 and a dynamic range of 0.005–100 U mL−1. The recovery of CA19-9 determination from serum samples was 101 to 113%. [ABSTRACT FROM AUTHOR]

Surface passivation engineering is an imperative way to improve photoelectrode performance for photoelectrochemical (PEC) water splitting. To the best of our knowledge, it has never been systematically reviewed in a feature article. In this review, we summarize various passivation materials and their preparation, characterizations by PEC measurements and some related spectral technologies. We highlight the features of the passivation effect that separate it from other modifications, such as cocatalyst decoration, and we demonstrate significant progress in combining surface passivation engineering with other interfacial modification strategies for the rational design of photoelectrodes. Ideas for future research on surface passivation modification for improving the performance of photoelectrodes are also proposed. [ABSTRACT FROM AUTHOR]

An integrated dual-signal bioassay was devised to fulfil thrombin (TB) ultrasensitive detection by integrating visualization with the photoelectrochemical technique based on G-quadruplex/hemin. During the process, branched sheet embedded copper-based oxides prepared with illumination and alkaline condition play a vital role in obtaining the desirable photocurrent. The switchover of photoelectrochemical signal was realized by the adjustable distance between electron acceptor G-quadruplex/hemin and interface materials due to dissociation of the Cu/Mn double-doped cerium dioxide (CuMn@CeO2)/DNA caused by the addition of TB. Then, CuMn@CeO2 transferred onto visual zones triggered catalytic reactions under the existence of 3,3′,5,5′-tetramethylbenzidine and hydrogen peroxide, making a variation in color recognized by the naked eye and providing visual prediction. Under optimized conditions, this bioassay protocol demonstrated wide linear ranges (0.0001–50 nM), high selectivity, stability, and reproducibility. More importantly, the proposed visual/photoelectrochemical transduction mechanism platform exhibits a lower background signal and more reliable detection results, which also offers an effective way for detecting other proteins and nucleic acids. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) technology is regarded as an attractive strategy to convert solar energy to a sustainable resource. This work constructed a BiVO 4 photoelectrode on FTO and modified with Ti 3 C 2 quantum dots (MQDs) through two-step calcination, and applied for PEC water splitting and H 2 O 2 determination. As-prepared BiVO 4 /Ti 3 C 2 QDs photoelectrode showed improved photoelectron-hole pairs separation under simulated solar light irradiation driven by the built-in electric field. The photo-generated electrons are transferred from BiVO 4 /Ti 3 C 2 QDs to the photocathode for water splitting H 2 production, showing a maximum photocurrent density of 2.44 mA·cm–2 at 1.23 V vs. RHE, which is about 2.5 times that of the pristine BiVO 4. While the H 2 O 2 was detected through the oxidation reaction by the photo-generated holes at the photoelectrode, which showed a wide linear range up to 18.1 mM, a low limit of detection of 0.17 μM, excellent stability, and good performance in the detection of real milk samples. Hence, the BiVO 4 /Ti 3 C 2 QDs photoelectrode is promising for simultaneous water splitting and H 2 O 2 determination with a simple, economical, and environmentally friendly approach. • Ti 3 C 2 quantum dots modified BiVO 4 were fabiricated for both PEC water splitting and H 2 O 2 determination. • The built-in electric field in BiVO 4 /Ti 3 C 2 QDs promotes the separation and transfer of electron-hole pairs. • Photo-generated electrons are consumed for H 2 production, while the holes are utilzed for H 2 O 2 detection. • The BiVO 4 /Ti 3 C 2 QDs indicates the potential in detecting H 2 O 2 in real applications. [ABSTRACT FROM AUTHOR]

The schematic diagram of NiFeO x /BiVO 4 photoanode for PEC water splitting. In this work, a straightforward electrostatic adsorption and pyrolysis methods were devised to convert bimetallic Ni-Fe-zeolitic imidazolate frameworks (Ni-Fe-ZIF) molecular sieve into NiFeO x oxygen evolution co-catalyst and modified on BiVO 4 photoanode surface (NiFeO x /BiVO 4). The optimized NiFeO x /BiVO 4 photoanode showed a high optical photocurrent density of 3.57 mA/cm2 at 1.23 V compared with reversible hydrogen electrode under AM 1.5G illumination with 4.4 times compared to the pure BiVO 4 photoanode. The NiFeO x /BiVO 4 composites photoanodes also exhibited the higher charge transfer efficiency of more than 77.8% than the pure BiVO 4 photoanode, indicating that the NiFeO x has excellent co-catalytic properties during PEC process. The improvement of photoelectric conversion efficiency can be attributed to the presence of NiFeO x layer with oxygen vacancies and more metal active sites on the BiVO 4 surface which promoted the separation and transport of photoelectron-hole pairs and the surface oxygen evolution kinetics, thus significantly improving the photocurrent density. [Display omitted] • The bimetallic Ni-Fe-ZIF with a positive potential on the surface. • The NiFeO x /BiVO 4 photoanode were prepared via Ni-Fe-ZIF by using electrostatic adsorption and pyrolysis methods. • The optimized NiFeO x /BiVO 4 with photocurrent density of 3.57 mA/cm2 for 4.4 times than pure BiVO 4 photoanode. • The NiFeO x as co-catalyst improves the surface oxygen evolution kinetics and photocurrent density. The water oxidation kinetics on the surface of bismuth vanadate (BiVO 4) photoanode is slow and the surface charge recombination is serious which hindering the photoelectrochemical (PEC) water splitting process. To enhance the PEC performance of BiVO 4 and expedite the water oxidation process, in this work, a straightforward electrostatic adsorption and pyrolysis methods were devised to convert bimetallic Ni-Fe-zeolitic imidazolate frameworks (Ni-Fe-ZIF) molecular sieve into NiFeO x oxygen evolution co-catalyst and modified on BiVO 4 photoanode surface (NiFeO x /BiVO 4). The optimized NiFeO x /BiVO 4 photoanode showed a high optical photocurrent density of 3.57 mA/cm2 at 1.23 V compared with reversible hydrogen electrode under AM 1.5G illumination with 4.4 times compared to the pure BiVO 4 photoanode. The NiFeO x /BiVO 4 composites photoanodes also exhibited the higher charge transfer efficiency of more than 77.8 % than the pure BiVO 4 photoanode, indicating that the NiFeO x has excellent co-catalytic properties during PEC process. The improvement of photoelectric conversion efficiency can be attributed to the presence of NiFeO x layer with oxygen vacancies and more metal active sites on the BiVO 4 surface which promoted the separation and transport of photoelectron-hole pairs and the surface oxygen evolution kinetics, thus significantly improving the photocurrent density. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of BiOBr NSAs possessing porous nanostructures by solvothermal method. • F-atom doping forms a large number of electron-rich regions in the structure. • F electron traps can effectively reduce recombination behavior during carrier transport. • BiOBr-F photoelectrode exhibits excellent PEC performance under light and applied bias voltage. Bismuth oxide semiconductors in the field of photoelectrochemical (PEC) water splitting face the problems of narrow photo response range and fast carrier compounding. On the basis of the above problems, we used a solvothermal method to prepare BiOBr nanosheet arrays (NSAs), which have a special structure that facilitates carrier transport. Subsequently, the F element was introduced into the bulk phase of BiOBr using a simple hydrothermal method. The results show that the BiOBr-F photoelectrode exhibits excellent photoelectrocatalysis performance under light and bias voltage. The photocurrent density of the BiOBr-F photoelectrode reached 28.35 μA cm−2 at 1.23 V vs. RHE, which is 2.01 times higher than that of the pure BiOBr, while a negative shift of the onset potential of 119 mV was obtained. The optical absorption tests show that the introduction of the F element forms an impurity energy level thereby extending the optical absorption range of BiOBr. Photoluminescence tests reveal that the introduction of F element effectively restricts the electron-hole pair recombination. This is due to the fact that the F atoms replace some of the O atoms in BiOBr to create electron traps, thus forming a large number of electron-rich regions in the structure, which in turn reduces the electron-hole pair recombination. This work provides an effective solution to reduce the recombination between carriers by creating electron traps in semiconductor materials through bulk phase doping. [ABSTRACT FROM AUTHOR]

The development of low-cost, ultra-stable catalysts for efficient oxygen evolution reactions (OER) is ideal for photoelectrochemical (PEC) water splitting. However, the severe charge recombination and slow kinetic reaction hinder the process of OER. Herein, we demonstrated the cooperative modification between Ti-MOF (NH 2 -MIL-125) and NiFeO x for significantly enhancing the oxygen evolution activity of BiVO 4 photoanodes, and the optimal photocurrent density has been reached to 3.92 mA cm−2 at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5 G). The integrated BiVO 4 /NH 2 -MIL-125/ NiFeO x photoanode system exhibits an applied bias photon-to-current efficiency (ABPE) of 2 % at 0.77 V RHE. More importantly, the photostablitily was significantly prolonged with a photocurrent retention rate of 92 % upon 20 h testing. The excellent performance is attributed to the construction of BiVO 4 /NH 2 -MIL-125 heterojunction, which improves the separation efficiency of photogenerated electron-hole pairs and the bimetallic NiFeO x co-catalyst reduces the surface reaction energy barrier. This work provides an effective approach for collaborative modification to improve the performance and stability of BiVO 4 photoanode PEC water splitting systems. [Display omitted] • The cooperative modification significantly enhanced the oxygen evolution activity of BiVO 4 photoanode. • The integrated BiVO 4 /NH 2 -MIL-125/NiFeO x photoanode system exhibits an ABPE over 2 % at 0.77 V RHE. • The BiVO 4 /NH 2 -MIL-125/NiFeO x achieves 92 % current retention after 20 h test. • The synergistic modification of NH 2 -MIL-125 and NiFeO x reduced the reaction barrier and achieved excellent stability. [ABSTRACT FROM AUTHOR]

The photodegradation and photoelectrochemical performance of Fe 2 O 3 catalyst is an encouraging visible-light induced catalyst owing to its less harmfulness, cheap and ecofriendly. However, owing to its quick charge carriers recombination rate and less lifespan of charge carriers obstructs its catalyst application. Therefore, it has been lately established that the construction of heterojunction with other semiconductor might be a possible method to improve its catalytic activity. Herein, a novel Z-scheme Fe 2 O 3 /g-C 3 N 4 heterostructure catalyst has been synthesized by a simple hydrothermal technique and studied its photoelectrochemical and photodegradation activity. The addition of g-C 3 N 4 greatly improves the light absorption ability light, reduced charge recombination rate and progress the charge transportation. The composite catalyst exhibited the superior photodegradation performance (97.8 %) of sulfamethoxazole antibiotic remedy within 30 min of visible light illumination. •OH and •O 2 – radicals show a key role for dye degradation activity, and proposed a possible photodegradation charge carrier transfer mechanism based on a potential band structures of composite catalyst. Furthermore, the prepared catalysts are further used to examine the photoelectrochemical properties for hydrogen generation. The Fe 2 O 3 /g-C 3 N 4 nanocomposite photoelectrode exhibited enriched photocurrent density (0.764 mA/cm2) than g-C 3 N 4 (0.271 mA/cm2) and Fe 2 O 3 (0.370 mA/cm2) photoelectrodes, which ∼ 2.8 and ∼2.1 folds greater photocurrent density than pure photoelectrodes. Electrochemical impedance spectroscopy analysis revealed that the composite electrode has minimal charge transfer resistance and greater electron transfer ability. Therefore, the current study presents a facile formation of Z-scheme catalyst and offers a sustainable method to eradicate water impurities and hydrogen generation by renewable solar energy. [Display omitted] • Novel Z-scheme Fe 2 O 3 /g-C 3 N 4 heterostructure catalyst was successfully synthesized. • Composite catalyst exhibited 97.8 % of antibiotic dye degradation within 30 min. • Composite showed 2.8 and 2.1 times higher photocurrent density than pure samples. • Composite is a suitable catalyst for PEC water oxidation and degradation activity [ABSTRACT FROM AUTHOR]

Developing efficient photocatalysts with highly active facets and appropriate cocatalyst hybridization to form heterostructure is a valid way to expedite the separation of photoexcited electron-hole pairs. Herein, a novel 0D/1D Ti 3 C 2 T x MXene/TiO 2 photocatalyst was fabricated for photoelectrochemical (PEC) water splitting and tetracycline antibiotic photocatalytic degradation. Meanwhile, highly-exposed TiO 2 nanotube arrays were prepared by electrochemical anodizing method, and Ti 3 C 2 T x nanoparticles with mixed terminal group were uniformly grown on the surface of TiO 2 through the hydrothermal and solvothermal process, respectively. Compared with pure TiO 2 , the Ti 3 C 2 T x /TiO 2 heterostructure exhibited different degrees of enhancement in PEC and photocatalytic degradation activities under simulated sunlight. The TNT/M-h sample yielded a photocurrent density of 1.77 mA cm−2 at 0 V (vs. SCE) and achieved a 95.57 % photocatalytic removal rate of tetracycline within 140 min. The excellent performance originated from the strong interfacial contact and work function discrepancy between the ordered tubular structure of TiO 2 and 0D Ti 3 C 2 T x nanoparticles, which realized the high-efficiency photogeneration and transfer of electron-hole pairs. • 0 D Ti 3 C 2 T x nanoparticles sensitized 1D TiO 2 nanotube arrays were fabricated through anodization coupled with hydrothermal/solvothermal methods. • The photoelectrochemical properties and photocatalytic degradation activity of TiO 2 and TiO 2 /Ti 3 C 2 T x were evaluated and analyzed. • The mechanism of the photocatalytic reaction was discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] For photoelectrochemical (PEC) water splitting, constructing heterojunctions and loading co-catalysts are effective means to realizing sufficient light absorption, effective photogenerated carrier separation and fast charge transport. However, during implementation, the PEC performance of the catalyst is affected by both parasitic light absorption and reflection and the change in energy band structure due to the creation of new interfaces. Herein, in order to minimize the effect of recombination of photogenerated electron-hole pairs on the catalyst PEC performance due to the nascent interface arising from the co-catalyst compounding, WO 3 and Ni/Co co-doped LaFeO 3 (LFO) are constructed as heterojunctions, in which NiCo-LFO acts both as a part of the heterojunction to enhance photogenerated carrier separation and a co-catalyst to enhance the conductivity and modulate the surface state density at the catalyst-electrolyte interface. The current density of NiCo-LFO/WO 3 reaches 3.92 mA cm−2, which is more than 7 times that of LFO/WO 3. This work provides a reference for the efficient water splitting of B-site doped, especially the co-doped perovskite oxide as multifunctional roles integrated with conventional photoelectrodes. [ABSTRACT FROM AUTHOR]

Herein, hydrothermal fabrication of CdO-g-C3N4 photocatalyst for a substantially better photocatalytic recital in water splitting is presented. The XRD analysis confirms the cubic phase of CdO-g-C3N4, whereas FTIR and UV-VIS studies revealed the presence of respective groups and a median band gap energy (2.55 eV) of the photocatalyst, respectively, which further enhanced its photo-electrochemical (PEC) properties. The SEM displays the oblong structures of g-C3N4 sheets and nano rod-like morphology of CdO and CdO-g-C3N4, respectively. The HR-TEM exhibits morphology & orientation of the grains and substantiates the polycrystal-line nature of CdO-g-C3N4 nanocomposite. The photocatalytic water-splitting concert is evaluated by PEC experiments under 1 SUN visible light irradiation. Linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) comprehend the CdO-g-C3N4 as a hydrogen evolution photocatalyst. A photocurrent density beyond ≥5 mA/cm2 is recorded from CdO-g-C3N4, which is 5–6 folds greater than pure CdO and g-C3N4. The efficient separation and transfer of charges allocated to CdO-g-C3N4 and fabricating heterojunctions between g-C3N4 and CdO suppresses the unfavorable electron-hole pairs recombination process. Thus, it recesses charge transfer resistance, augmenting enhanced photocatalytic performance under 1 SUN irradiation. [ABSTRACT FROM AUTHOR]

There are tremendous efforts to realize the idea of employing photoelectrochemical (PEC) technology for generating chemical energy from solar energy. The most important feature of this technology is to coordinate the energetics of an electrochemical reaction with the solar spectrum. So, the photoelectrochemistry of a semiconducting material plays a vital role in this arena. Exploring an efficient and stable semiconductor material for such purpose is an essential prospect. There are several sulfide selenide‐based semiconductors viz. II‐VI (Zn/Cd = S/Se) semiconductors those exhibit high potential in PEC application. Nonetheless, they suffer by certain corrosion issues, which are important to be reviewed and are discussed here. This review highlights the significant role of cadmium chalcogenides among various materials explored in this technology. CdS is the most studied system among all those with perfect band gap and band‐edge position exhibiting material, desired for photoanode in PEC cell. Next, recent progresses achieving enhancement in the performance of CdS photoanodes by doping, modifying the surface, morphology reconstruction, and engraving heterostructure is discussed in detail. The role of the nanostructured techniques, improved photo electrochemistry with redox couples, and advanced interfacial and band gap engineering is explored to overcome the lack of chemical stability of CdS. The review concludes with the bright scope of CdS as an efficient PEC material in the form of combined semiconductor systems with an optimum band gap, bandedge, and their complimentary properties rather than a single component material. [ABSTRACT FROM AUTHOR]

Earth‐abundant Cu2O is a promising photocathode material for photoelectrochemical (PEC) water splitting. However, the serious photocorrosion and low efficiency retard its practical applications. Herein, a porous Cu‐based metal–organic framework material, Cu3(BTC)2, as surface passivation layer is grown on Cu2O nanorod arrays (NRARs) photocathode by in situ surface/interfacial growth. Compared to conventional Cu2O photocathodes, the optimized Cu2O/Cu3(BTC)2 NRARs exhibit two times higher photocurrent density, ≈2.73 mA cm−2 at 0 VRHE under visible light irradiation, and the maximum incident photon to converted electron (IPCE) performance reaches 45% (450 nm). It is demonstrated that the Cu3(BTC)2 layer synergistically passivates interfacial defects, forms p–n junctions at the Cu2O/Cu3(BTC)2 interface, and introduces active sites catalyzing the hydrogen evolution reaction (HER), improving charge separation, transfer, and utilization efficiency. Moreover, the oxidative Cu2O photocorrosion is inhibited owing to the accelerated charge dynamics at the Cu2O/Cu3(BTC)2 interface and the hole‐scavenging ability of Cu3(BTC)2, meanwhile, reductive Cu2O photocorrosion at Cu2O/Cu3(BTC)2 is also attenuated by catalyzing the water reduction reaction that competes for photoelectrons and sustaining balanced "Cu2+(Cu+)/Cu0" cycles. [ABSTRACT FROM AUTHOR]

• Single micro-bubble is generated by focusing the laser to form a micron-sized spot. • Bubble growth is observed in situ by high-speed microscopic camera. • PEC performance of TiO 2 photoanode in KOH is better than that of NaOH and LiOH. • The marangoni flow turn away from the electrode and hinder the bubble detachment. • The Solutal Marangoni effect is the dominant factor affecting bubble dynamics. 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 TiO 2 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. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative FeOOH/BiVO 4 composite photoanode enhances glycerol conversion efficiency. • Electron-rich Bi-O-Fe active sites crucial for selective glyceraldehyde production. • Achieves a 14.98-fold increase in GLAD output compared to pristine BiVO 4. Heterojunction engineering is crucial for converting glycerol into valuable organic compounds via photoelectrochemistry, but controlling the structure precisely to enhance conversion efficiency remains challenging. In this study, we effectively created a compound photoanode with unique active regions by growing amorphous FeOOH co-catalysts on BiVO 4. The results revealed that the Fe2+ ions located on the surface of the co-catalyst FeOOH facilitate the glycerol transformation process, whereas the electron-rich Bi-O-Fe sites contribute significantly to the preferential transformation of glycerol into glyceraldehyde. These sites not only serve as primary reactive centers, catalyzing the adsorption and conversion of glycerol hydroxyl clusters, but also act as repositories for trapping holes. This dual function accelerates the breaking of C H bonds to generate glycerol aldehyde and exhibits excellent desorption capacity, ensuring exceptional product selectivity. This led to exceptional glyceraldehyde production (709mmol m-2 h−1) compared to pristine BiVO 4 , showcasing a 14.98-fold increase. [ABSTRACT FROM AUTHOR]

In 2 S 3 –In 2 O 3 films were used as photoelectrodes and photocatalysts for hydrogen production. The films were grown using a hydrothermal method for different reaction times (4, 6, 8, 12, 18 and 24h). The difference in the reaction time influences the presence of other crystalline phases, such as β-In 2 S 3 , In 2 O 3 , Ti 3 S 4 , and Ti 5 S 8 , on the film structure; the presence of these elements was verified by the XPS results. Furthermore, the mixture of phases generates different morphologies such as flowers, pyramids, and sheets. The best photoelectrochemical results were obtained from the films deposited at a reaction time of 6, 8, and 12 h, as these films have an OCP value of ∼0.3586, 0.3791 and 0.4771 V RHE and a photocurrent density of 3, 1.92, and 1.5 μA•cm−2 at 1.23 V vs. RHE, respectively. According to these results, the 12h/In 2 S 3 –In 2 O 3 film has the highest donor density and the lowest Debye length, which enhances the efficiency of photogenerated electrons and electron-hole separation. Moreover, the highest photocatalytic hydrogen production was achieved with the 12h/In 2 S 3 –In 2 O 3 film, which, in addition to presenting the most optimal photoelectrochemical properties, also has defects such as oxygen deficiencies, In i and V In , which could act as traps for electrons in the recombination process, increasing the reduction reactions at low energy and enhancing hydrogen production. • Deposit of In 2 S 3 –In 2 O 3 photoelectrodes and photocatalysts for H 2 production. • Reaction time influences the presence of different crystalline phases. • In 2 S 3 –In 2 O 3 photocurrent density between 1.5 and 3 μA.•cm−2 at 1.23 V vs. RHE. • In 2 S 3 –In 2 O 3 with highest donor density has the best efficiency in H 2 production. [ABSTRACT FROM AUTHOR]

In this study, WO 3 thin-film photoelectrodes were grown on fluorine-doped tin oxide (FTO) substrates using the spin coating method. The H 2 WO 4 precipitate underwent various washing treatments to prepare the Na 2 WO 4 precursor solution, which was subsequently used for growing photoelectrodes. We found that washing with the H 2 WO 4 precipitate changed the Na + ion concentration and pH of the precursor solution containing the H 2 WO 4 precipitate and subsequently affected the thickness, X-ray diffraction (XRD) peak intensity, optical energy bandgap, flat-band potential, and photoelectrochemical (PEC) properties of the WO 3 photoelectrode. In particular, the Na + ions in the H 2 WO 4 precipitate solution negatively affected the PEC properties by causing photogenerated electron–hole recombination and worsening the adhesion between the substrate and the WO 3 thin film. Therefore, H 2 WO 4 precipitate washing treatment is crucial for reducing the Na + ion concentration in solutions containing H 2 WO 4 precipitate. Consequently, among the samples grown using different numbers of washing treatments, the sample grown using 12 precipitate washing treatment cycles exhibited the highest photocurrent density of 1.37 mA/cm2 and a photostability of 97.5 %. In this study, the morphological, structural, optical, electrical, and PEC properties of WO 3 photoelectrodes subjected to H 2 WO 4 precipitate washing treatment were systematically analyzed. (Top) Schematic diagram for the photoelectrochemical cell reaction(Bottom, Left) Na + ion concentration of the solution containing the H 2 WO 4 precipitate according to the number of washing treatment cycles(Bottom, Right) PEC performance of WO 3 photoelectrodes prepared with different numbers of washing treatment cycles in 0.5 M Na 2 SO 4 (pH 5.7): photocurrent density at 1.7 V (vs. SCE). [Display omitted] • WO 3 thin films were grown on an FTO substrate using a spin-coating method. • The photoelectrochemical properties of WO 3 photoelectrodes were improved by controlling Na + ion concentration through H 2 WO 4 precipitate washing. • The photoelectrochemical properties largely depended on the number of H 2 WO 4 precipitate washing treatments. [ABSTRACT FROM AUTHOR]

Improving the kinetics of oxygen evolution is crucial for enhancing the performance of photoelectrochemical (PEC) water splitting. Herein, this study utilizes a chemical self-growth method to grow NiFe tannic acid complex (NFTA) and Co(OH) 2 on the surface of BiVO 4 photoanode (BiVO 4 /NFTA/Co). As a result, the synergistic effects of NFTA and Co(OH) 2 layers promote the efficiency and stability of BiVO 4 photoanode towards PEC water oxidation. The photocurrent density of the obtained BiVO 4 /NFTA/Co photoanode reaches 4.97 mA cm−2, which is significantly greater than those of BiVO 4 /NFTA (4.36 mA cm−2), BiVO 4 /Co (2.51 mA cm−2), BiVO 4 (1.34 mA cm−2), respectively. Detailed analysis confirms that NFTA could provide an efficient way to hasten the transfer of photo-generated holes on the photoanode surface and diminish the surface charge transfer resistance. In other hand, Co(OH) 2 could be served as a cocatalyst to accelerate charge transfer for efficient oxygen evolution reaction as well as a protective layer to maintain the long-term stability of NFTA on the surface of BiVO 4 during water oxidation. Such double oxygen evolution co-catalysts decoration strategy paves an effective pathway to enhance the PEC water oxidation performance of BiVO 4 photoanode. [Display omitted] • NiFe-tannic acid and Co(OH) 2 co-modified BiVO 4 realizes excellent PEC activities. • The enhanced PEC performance is due to the promoted charge transfer. • BiVO 4 /NFTA/Co photoanode attains 4.97 mA cm−2 at 1.23 V RHE with good durability. [ABSTRACT FROM AUTHOR]

Sensitive detection and effective inactivation of bacteria are essential in preventing foodborne bacterial infection that poses a significant threat to human health. Herein, a near-infrared (NIR)-driven multifunctional photoelectrochemical (PEC) biosensor was constructed for detection and inactivation of S. aureus. Based on the covalent bonding between amine and carboxyl groups, carboxyl-functionalized SA31 aptamer was immobilized on the PDA/MnO 2 photoelectrode. In the presence of S. aureus , SA31 aptamer can specifically capture S. aureus , causing the decrease of photocurrent signal owing to steric hindrance effect. Leveraging photocurrent-off signal, there existed a satisfied linear relationship between the photocurrent variation and the logarithm of S. aureus concentration, achieving a wide linear range from 10 to 107 CFU/mL with a low detection limit of 2.0 CFU/mL. Notably, PDA/MnO 2 with peroxidase-like activity facilitated the catalytic oxidation of S. aureus with assistance of hydrogen peroxide (H 2 O 2) to cause the inactivation of S. aureus. Desorption of inactivated S. aureus from the photoelectrode led to a recovery of photocurrent signal, enabling a "signal on" switch. Simultaneously, the excellent photothermal performance of the PDA/MnO 2 converted light energy into heat energy under the irradiation of NIR light (808 nm, 1.5 W/cm2), triggering the synergistic antibacterial effect against S. aureus (97.36%). This work provides a novel strategy for fabricating the detection and inactivation of bacteria in practical applications. [ABSTRACT FROM AUTHOR]

The catalytic reactions of photoelectrochemical water splitting attracts tremendous attention as a promising strategy for clean energy production. And the research on reaction mechanism is particularly important in design and developing new catalysts. In this work, the special electrochemical tool of interdigitated array (IDA) electrodes was utilized in investigating the photoelectrochemical oxygen evolution reaction process and detecting the reaction product in situ with the generation-collection mode. TiO2 was taken as a model catalyst and was decorated onto the IDA generator electrode through an electrophoresis method, so that the photoelectrochemical water splitting can take place on the IDA generator and the reaction product can be detected directly with the IDA collector in real time. It is found that TiO2 can be successfully decorated onto the surface of IDA electrode with the expected photoelectrochemical activity, and the generation-collection mode reveals and distinguishes the production of O2 from the overall photoelectrochemical current on TiO2 generator. The mass transfer process of O2 from the TiO2 generator to the collector could be observed as well. Large overall current at high potential range indicates the possible increasing production of the byproducts or nonfaradaic current. [ABSTRACT FROM AUTHOR]

The catalytic reactions of photoelectrochemical water splitting attracts tremendous attention as a promising strategy for clean energy production. And the research on reaction mechanism is particularly important in design and developing new catalysts. In this work, the special electrochemical tool of interdigitated array (IDA) electrodes was utilized in investigating the photoelectrochemical oxygen evolution reaction process and detecting the reaction product in situ with the generation-collection mode. TiO2 was taken as a model catalyst and was decorated onto the IDA generator electrode through an electrophoresis method, so that the photoelectrochemical water splitting can take place on the IDA generator and the reaction product can be detected directly with the IDA collector in real time. It is found that TiO2 can be successfully decorated onto the surface of IDA electrode with the expected photoelectrochemical activity, and the generation-collection mode reveals and distinguishes the production of O2 from the overall photoelectrochemical current on TiO2 generator. The mass transfer process of O2 from the TiO2 generator to the collector could be observed as well. Large overall current at high potential range indicates the possible increasing production of the byproducts or nonfaradaic current. [ABSTRACT FROM AUTHOR]

Dedications to achieve the highly efficient metal oxide semiconductor for the photoelectrochemical water splitting system have been persisted to utilize the TiO2 as the promising photoanode material. Herein, we report notable progress for nanostructured TiO2 photoanodes using facile sequential one-pot hydrothermal synthesis and annealing in hydrogen. A photocurrent density of 3.04 mA·cm−2 at 1.23 V vs. reversible hydrogen electrode was achieved in TiO2 nanorod arrays annealed in hydrogen ambient, which is approximately 4.25 times higher than that of pristine TiO2 annealed in ambient air. 79.2% of incident photon-to-current efficiency at 380 nm wavelength demonstrates the prominence of the material at the near-UV spectral range region and 100 h chronoamperometric test exhibits the stability of the photoanode. Detailed studies regarding crystallinity, bandgap, and elemental analysis provide the importance of the optimized annealing condition for the TiO2-based photoanodes. Water contact angle measurement displays the effect of hydrogen annealing on the hydrophilicity of the material. This study clearly demonstrates the marked improvement using the optimized hydrogen annealing, providing the promising methodologies for eco-friendly mass production of water splitting photoelectrodes. [ABSTRACT FROM AUTHOR]

A Si/ZnO/Cu2O p‐n‐p heterojunction potential well with electron tunnels is fabricated for selective photoelectrochemical CO2 reduction to ethanol. This heterojunction is formed by growing n‐type ZnO nanosheets between defect‐rich p‐type Cu2O nanoparticles and nanoporous p‐type Si. Due to the existence of this potential well, the photogenerated electrons are trapped and accumulate inside n‐ZnO at low biases with the assistance of a ≈0.6 V built‐in potential, and escape into the Cu2O defect band. Under simulated sunlight, the Si/ZnO/Cu2O photocathode exhibits an onset potential of 0.2 V versus reversible hydrogen electrode (RHE) for aqueous photoelectrochemical CO2 reduction. Due to the confined electron energy in tunneling, the product selectivity is substantially tuned from CO or formate to ethanol, with an excellent Faradaic efficiency of ethanol over 60% at 0 V versus RHE. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) cytosensors, a combination of the PEC process and the living‐cell assay, have emerged as a powerful tool in the analytical and biological science. This mini review provides a brief introduction of this arena and summaries the key steps about the development of PEC cytosensors with representative examples, followed by future prospects based on our own opinions. [ABSTRACT FROM AUTHOR]

Propyl gallate (PG) as one of the most important additives has been widely used to prevent or slow the oxidation of foods in the food industry. In this work, Cu3(PO4)2/BiVO4 composite is synthesized through two hydrothermal processes. With visible light irradiation, the Cu3(PO4)2/BiVO4 composites modified PEC platform displays a superior anode photocurrent signal. The PEC sensor showed a wide linear range from 1 × 10−10 to 1 × 10−3 mol L−1 with a detection limit as low as 0.05 × 10−10 mol L−1. The Cu3(PO4)2/BiVO4 photoelectrochemical (PEC) sensor is designed and characterized by electrochemical impedance. Compared with GCE/BiVO4 and GCE/Cu3(PO4)2, the GCE/Cu3(PO4)2/BiVO4 has a higher photocurrent response. In addition, the sensor is highly selective for samples containing other antioxidants. Furthermore, the sensor can be used to detect PG in edible oil samples with satisfactory results. The recoveries of propyl gallate in edible oil ranged from 95.5 to 101.8%. The results show that Cu3(PO4)2/BiVO4 composites can be used to analyze PG in different edible oil samples, which are beneficial for food quality monitoring and reduce the risk of PG overuse in food. [ABSTRACT FROM AUTHOR]

Developing highly efficient and durable semiconductor photoelectrodes has become a great significance for the synthesis of clean fuels and valuable chemical products via photoelectrochemical (PEC) cell. Herein, TiO2 nanotube array–supported amorphous cocatalyst NiFe oxyhydroxides (NiFe-OOH/TiO2 NTs) were constructed by the electrodeposition method. Surprisingly, the prepared amorphous NiFe oxyhydroxides were uniformly decorated on the surface of TiO2 nanotubes without the agglomeration, which were conducive to the separation and transfer of photogenerated carriers. These nanoarchitectonics of NiFe-OOH/TiO2 NTs were favorable for promoting both the water oxidation and the selective oxidation of benzyl alcohol (BA). NiFe-OOH/TiO2 NTs demonstrated admirable stability for the water oxidation, reaching the photocurrent density of 0.49 mA cm−2 at 1.23 V vs. RHE. Furthermore, the conversion efficiency and the selectivity of BA to benzaldehyde under neutral conditions were as high as 67.7% and 84.7%, respectively. This work may provide a simple method for preparing efficient and durable photoelectric electrodes to improve the oxidation performance of PEC cell. [ABSTRACT FROM AUTHOR]

In this manuscript, we propose to produce and characterize a photoelectrodes based on hematite Fe2O3/Ni(OH)2, without hazardous chemical substances (non-CMR substances) and no ozone emanation in handmade photocell. Fe2O3 and Fe2O3/Ni(OH)2 photoanodes were synthesis by hydrothermal method, and were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energydispersive X-ray analysis (EDX), and ultraviolet–visible (UV–Vis) analysis. The photoelectrochemical (PEC) performances of the Fe2O3 and Fe2O3/Ni(OH)2 films was examined by linear sweep voltammetry techniques, cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy analysis, which confirm that the highest photocurrent about 0.344 mA/cm2 at 0.5 V vs Hg/HgO was obtained for the Fe2O3/Ni(OH)2 photoanode in 0.1 M urea than 0.09 mA/cm2 without urea. Result provided in this work can provide an imperative guideline for the design of efficient photocatalysis application using Fe2O3/Ni(OH)2 for photoelectrochemical urea conversation. [ABSTRACT FROM AUTHOR]

Efficient and long-term photoelectrochemical (PEC) hydrogen liberation from hydrazine hydrate was achieved using CdS nanorod arrays (CdS NRs) as the photoelectrode. Under light irradiation, the CdS photoelectrode exhibited high efficiency and stability for the anodic oxidation of N2H4·H2O with high selectivity for hydrogen production at the counter cathode. The yield and Faradic efficiencies (FE) of hydrogen from N2H4·H2O solution under mild conditions were determined to be 658 μmol/cm2 and 90%, respectively, after 5 h of operation. The photocurrent density of the CdS electrode in electrolyte with N2H4·H2O reached 7.6 mA/cm2 at 1.23 V versus RHE, five times higher than that in N2H4·H2O free electrolyte. And the persistence of CdS electrodes in electrolytes with N2H4·H2O was more than 100 h, while in N2H4·H2O free electrolytes, it was less than 100 s. An obvious cathodic shift of the photocurrent onset potential of about 300 mV was also observed. Furthermore, the kinetics of PEC oxidation of N2H4·H2O were further tested. In addition, it is expected that this work may provide a strategy to stabilize other unstable photoelectrodes for a wide range of applications and supply a way to produce hydrogen by photoelectrochemical decomposition of N2H4·H2O. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) photodetectors have attracted increasing attention in military and civilian fields.In this work, the prepared TiO2-graphene composite was fabricated by hydrothermal synthesis method and it was used in photoelectrochemical type photodetector for UV detection. The results of the photoelectrochemical measurements demonstrate that the TiO2-graphene composite have a remarkable enhancement on photoresponse compared to pure TiO2, which is effectively demonstrate the introduction of graphene will reduce the probability of electron-hole recombination and increase the photocurrent of light detection. In addition, owing to the unique solid-liquid contact mechanism of PEC-type photodetector, it can work under 0 V bias and exhibited excellent photoresponse ability that can reach11uA/W at the UV wavelength of 365 nm. Moreover, the as-prepared TiO2-graphene composite based photodetector possessed preferable performance with the weak irradiation. Even if the light intensity reduced to 6 mW/cm2, the photocurrent density can also reach to 5 uA/cm2. With the excellent absorbtion of the UV and remarkable self-powered ability make the TiO2-graphene composite based PEC-type photodetector have great promising on UV detection field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dendritic hematite nanorods were generated through hydrothermal treatment. • Unoccupied surface Fe site can be coordinated with ferrous lactate complex. • Onset potential negatively by 100 mV with enhanced photocurrents (200%) was observed. • Modified samples exhibit excellent charge transfer properties and good stability. • Possible charge transfer pathways during water oxidation were proposed. Hematite (α-Fe 2 O 3) has been intensively studied as a promising photoanonde material for water splitting. This paper reports a facile method to prepare dendritic hematite nanorods and an active catalytic interface was constructed by coordinating ferrous lactate layers. A negative shift of 100 mV for onset potential and significant enhancement (200%) of photocurrent were observed for the modified hematite photoanodes. It was found that ferrous lactate decorated samples showed distinct catalytic effect for water oxidation only in illuminated condition. XPS and a series photo-electrochemical analysis reveal that Fe (II) site in the surface bonded ferrous lactate possessed distinguished photo-generated charge transfer properties and excellent stability during the reaction. The corresponding mechanism for water oxidation over catalytic surface was proposed. The result provides a facile and reliable surface modification method for efficient PEC water oxidation. [ABSTRACT FROM AUTHOR]

Hematite (α-Fe2O3) is a potential photoanode material for photoelectrochemical (PEC) water splitting, but its short hole diffusion length and low water oxidation kinetics prevent its practical application. In general, the hole transport rate and the water oxidation kinetics could be improved by modifying the oxygen evolution cocatalysts (OECs) in the proper way. In this work, we designed and synthesized a bimetallic phosphides NiCoP nanoparticles (NPs) modified (Ti, Zr)-codoped hematite photoanode (TZ-H) by a facile spin coating method to achieve the uniform and close interface contact of semiconductor/OECs. Under the optimal conditions, the as-prepared photoanode exhibits high and stable PEC performance with a current density of 2.38 mA/cm2 at 1.23 V vs. RHE, which is one of the best performances of noble-metal-free hematite-based photoanodes for water oxidation. Moreover, the surface efficiency of charge separation is improved by NiCoP modification, which is increased from 59% to 91% at 1.23 V vs. RHE and reached nearly 99% at higher potential. This work not only proves that NiCoP NPs are outstanding OECs but also provides a new strategy for the design of noble-metal-free semiconductor/OECs photoanodes with high-quality interface contact. [ABSTRACT FROM AUTHOR]

Cu 2 ZnSnS 4x Se 4(1-x) (CZTSSe) has recently attracted much attention for solar water splitting due to its high absorption efficient and tunable bandgap. However, high quality CZTSSe thin films with good quality and adherence with the substrate are mainly based on physical deposition method, such as magnetron sputtering, which is expensive and energy consuming processes. Here, we have developed a novel and low-cost solution fabrication method and CZTSSe electrodes were synthesized at low temperature by hydrothermal treatment of chemical bath deposited SnS films. The quality and phase purity of CZTSSe thin films were greatly improved after annealing process and the effect of SnS thickness to the physical and photoelectrochemical (PEC) properties of CZTSSe thin films were detailedly studied. The fabrication of FTO/CZTSSe/CdS/TiO 2 /Pt photocathode improved the PEC properties of CZTSSe thin films greatly and the highest water splitting photocurrents of 7.2 mA/cm−2 had been achieved under simulated solar illumination. Furthermore, the electrode showed good stability and had a good incident photon-to-current efficiency (IPCE) response in the visible light range. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is a promising method for transforming solar energy into clean and sustainable energy. However, PEC is severely limited, and they cannot achieve the predicted photocurrent density owing to the severe photochemical deterioration of the electrode and the recombination of photogenerated carriers. In this study, BiVO 4 /Co-diethylenetriamine Penta (methylene phosphonic acid) (BVO/Co-DTPMP) co-catalyst was successfully prepared as a nanoporous photoanode. Diethylenetriamine Penta (methylene phosphonic acid) was crosslinked with Co ions and coated on the BiVO 4 surface by successive ionic layer adsorption and reaction (SILAR) to reduce fast recombination, which correlated with the BiVO 4 photoanode. Various characterization and PEC measurements were conducted, revealing that the co-catalyst thin layer enhanced the charge separation and electrons transfer which significantly affected on the PEC performance of BiVO 4 , and the current density by BVO/Co-DTPMP was 4 mA cm−2 at 1.23 V vs. RHE. Furthermore, the co-catalyst exhibited improved charge transport and long-term stability. [Display omitted] • Amorphous metal organic complex layer (Co-DTPMP) coated on BiVO 4 via SILAR method. • Co-DTPMP layer enhanced the charge separation efficiency & interfacial kinetics. • Coated BiVO 4 enhanced photocurrent density eight times compared to BiVO 4 photoanode. • The photoconversion efficiency of the photoanode reached around 1.37 %. [ABSTRACT FROM AUTHOR]