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Colloidal quantum dots (QDs) are promising building blocks in optoelectronic devices, mainly due to their size/shape/composition‐tunable properties. Core–shell QDs, in particular, offer enhanced stability, mitigated photoluminescence blinking, and suppressed non‐radiative recombination compared to plain QDs, making them highly promising for energy conversion applications such as photovoltaic devices, luminescent solar concentrators, solar‐driven hydrogen production, and light‐emitting diodes. Here, a comprehensive analysis of core–shell QDs in energy conversion technologies is provided. Emerging design strategies are explored and various synthetic methods focusing on optimizing band structure, band alignment, and optical properties are critically explored. Insights into the structure‐property relationship are discussed, highlighting recent advancements and the most effective strategies to enhance energy conversion performance. The review is concluded by addressing key challenges and proposing future research directions, emphasizing the need for rational design, precise synthesis, effective surface engineering, and the integration of machine learning to achieve optimized properties for technological applications. [ABSTRACT FROM AUTHOR]

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]

The pursuit of sustainable energy has intensified the exploration of hydrogen as a clean energy carrier, with photoelectrocatalytic water reduction emerging as a green approach to harness solar energy. Graphitic carbon nitride (g‐C3N4), recognized for its stability and non‐toxicity, presents limitations in photoconversion efficiency due to rapid electron‐hole recombination and narrow light absorption range. To address these challenges, herein, a cryo‐electrochemical deposition strategy is introduced to synthesize g‐C3N4 loaded with gold single‐atom catalysts (Au1), enhancing charge separation and light absorption. The atomic dispersion of Au1 on g‐C3N4 significantly elevates photoelectrocatalytic hydrogen production, achieving a record yield rate on the Au1(14.5%)/g‐C3N4 sample. Density functional theory (DFT) calculations and comprehensive characterizations reveal the role of Au1 in modulating the electronic structure and improving charge carrier dynamics. The findings underscore the potential of single‐atom catalysis in advancing photoelectrocatalytic water reduction systems for solar energy conversion and clean energy production. [ABSTRACT FROM AUTHOR]

As an important compound in various industries and metabolic processes in the human body, high concentrations of hydrogen peroxide (H2O2) can cause serious injuries to humans and other organisms. Thus, it is of great significance to develop a rapid, sensitive, and practical method for the detection of H2O2. Herein, carbon quantum dot-mediated CoAl-layered double hydroxide (CQDs/CoAl-LDH) was decorated on a hematite (α-Fe2O3) photoelectrode via a simple one-pot hydrothermal method. The resultant CQDs/CoAl-LDH/α-Fe2O3 exhibited excellent photoelectrochemical (PEC) sensing toward H2O2 with high sensitivities of 92.10 and 39.27 μA mM–1 cm–2 in the linear range of 0.001–0.9 and 0.9–2 mM, respectively, and low limit of detection (0.02 μM, S/N = 3) at 0 V vs SCE, as well as good selectivity, stability, reproducibility, and reliability. The investigation of the mechanism revealed that CQDs could not only mediate the growth of CoAl-LDH to expose active sites but also improve the electroconductivity of CoAl-LDH to facilitate charge transfer, while CoAl-LDH could rapidly extract photogenerated holes to improve charge separation and provide catalytic active sites for H2O2 oxidation. The synergistic effect of the CQDs and CoAl-LDH significantly boosted the PEC activity of α-Fe2O3 for H2O2 oxidation. The strategy for boosting the PEC performance is of great importance for other semiconductor photoelectrodes. [ABSTRACT FROM AUTHOR]

Solar hydrogen production is a promising pathway for sustainable CO2-free hydrogen production. It is mainly classified into three systems: photovoltaic electrolysis (PV-EC), photoelectrochemical (PEC) system, and particulate photocatalytic (PC) system. However, it still has trouble in commercialization due to the limitation of performance and economic feasibility in the large-scale system. In this review, the challenges of each large-scale system are, respectively, summarized. Based on this summary, recent approaches to solving these challenges are introduced, focusing on core components, fabrication processes, and systematic designs. In addition, several demonstrations of large-scale systems under outdoor conditions and performances of upscaled systems are introduced to understand the current technical level of solar-driven hydrogen production systems for commercialization. Finally, the future outlooks and perspectives on the practical application of large-scale solar-driven hydrogen production are discussed. [ABSTRACT FROM AUTHOR]

Efficient light absorption and photoinduced electron transfer from the g-C 3 N 4 (CN) continue to be an ongoing challenge in photocatalytic hydrogen production. Nanodimensional metallic cocatalysts can offer superior electron transport pathways, thereby augmenting photocatalytic activity. In our work metallic NiCo 2 O 4 (NCO) acts as an electron acceptor cocatalyst in a 2D-2D Schottky junction with CN and 0D silver (Ag) functions as a hot electron donor via the localized surface plasmon resonance phenomenon. The novel Ag–CN–NCO nanocomposite was shown to boost visible light absorption while inhibiting charge carrier recombination through optical experiments. The Ag–CN–NCO nanocomposite demonstrated superior photocatalytic activity compared to CN loaded with a single cocatalyst, producing hydrogen at a rate of approximately 2320 μmol/g/h. Additionally, Ag–CN–NCO produced a lower overpotential and almost five times more photocurrent density than CN, as demonstrated by photoelectrochemical studies. This work highlights the development of a novel charge transfer pathway by combining two co-catalysts with different functions and their combined action on the photocatalytic hydrogen production process. [Display omitted] • 0D Ag as an electron donor cocatalyst via LSPR effect. • 2D metallic NiCo 2 O 4 as an electron donor cocatalyst via Schottky junction. • Investigation of unique interfacial charge transfer pathway. • Synergistic effects of Schottky junction and LSPR as dual strategies. • Hydrogen production rate of 2320 μmol/g/h. [ABSTRACT FROM AUTHOR]

A photocurrent enhancing photoelectrochemical (PEC) immunosensor was developed for chloramphenicol (CAP) detection based on cation exchange reaction. The efficient split-type PEC immunosensor combined with controlled-release strategy was established using the ZnIn2S4/TiO2/Ti3C2 MXene (ZIS/T/M) composite as the photoactive material and CuO as the signal response probe. In the presence of target CAP, CuO-labeled CAP antibody (CuO-mAb) was introduced onto the microplate via a competitive-type immunoassay. Under acidic conditions, a large amount of Cu2+ released from CuO-mAb, which triggered a cation exchange reaction with the Zn2+ in ZIS/T/M-modified photoelectrode to generate CuxS, resulting in enhancing the photocurrent. As a result, the quantitative detection of CAP was achieved by detecting the photocurrent change. Under optimized conditions, the linear range of the sensor was 1 pg/mL to 50 ng/mL, and the detection limit was 0.24 pg/mL. The excellent PEC behavior of ZIS/T/M composite could be attributed to the fact that heterojunction formation improved the migration and separation of the photocarrier. Additionally, by virtue of the photocurrent-enhancing strategy via cation exchange reaction and the controlled releasing signal amplification method of ion, the PEC immunosensor has high sensitivity and satisfactory accuracy, offering great potential applications in the determination of CAP. [ABSTRACT FROM AUTHOR]

A one-step hydrothermal technique was utilized to generate WO3 nanosheets on fluorine-doped tin oxide (FTO) (WO3/FTO), which were subsequently modified with ZnIn2S4 microspheres to create a Z-scheme heterojunction ZnIn2S4/WO3/FTO electrode for Cu2+ detection. The heterojunction exhibited excellent photoelectric conversion efficiency, which was nearly 2.5-fold and 5.1-fold greater than that of WO3 and ZnIn2S4. The reduced photoelectrochemical response signal was caused by the formation of CuxS and enabled Cu2+ assessment in water samples. After optimizing the experimental conditions, the anodic photocurrent at 0 V vs SCE in 0.100 M phosphate buffer (pH 7.0) containing 0.100 M L-ascorbic acid was linear with the common logarithm of Cu2+ concentration from 5.00 nM to 100 μM, with a limit of detection of 1.2 nM (S/N = 3). Satisfactory recovery results were obtained in the analyses of Xiangjiang River water samples. [ABSTRACT FROM AUTHOR]

Bi2Se3 has a unique surface state and excellent electron transport performance, but because of its narrow band gap, Bi2Se3‐based photodetectors are difficult to achieve high response to ultraviolet (UV) light. In this paper, the TiO2/Bi2Se3 heterostructure was constructed by spin‐coating TiO2 on Bi2Se3 film, and TiO2/Bi2Se3 heterostructure‐based photoelectrochemical (PEC) photodetector was constructed, and a series of measurements were carried out. The measure results showed that the photoresponse performance of TiO2/Bi2Se3 heterostructure‐based photodetector was improved in the visible region, and the performance in the UV was further improved. This is because the type ii band alignment between TiO2 and Bi2Se3 is beneficial for the effective separation and transfer of photogenerated electron‐hole pairs, reducing recombination losses and enhancing the overall photoresponse. In addition, under the action of the built‐in electric field formed by the heterostructure, the photogenerated electrons and holes are easier to separate, which reduces the recombination probability of the photogenerated electron‐hole pair and improves the photoelectric conversion efficiency. In the UV, TiO2/Bi2Se3 heterostructure can make more efficient use of the light absorption characteristics of TiO2 and absorb more photons, resulting in a larger photocurrent. These results indicate that TiO2/Bi2Se3 heterostructure‐based photodetector has great application potential in the UV. [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]

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Zn doped CuBi2O4 photocathodes are prepared by using a low‐cost solution‐based spray pyrolysis method. The doping of Zn in CuBi2O4 promotes the separation and migration of carriers and effectively increases the carrier density. Compared with CuBi2O4 alone, the photoelectrochemical activity of the Zn doped CuBi2O4 photoelectrode is improved with the photocurrent density of −0.56 mA/cm2 at 0.4 V vs. RHE. This improvement is due to the lower electronegativity of Zn, which leads to the covalent increase of Cu−O and Bi−O bonds in CuBi2O4, which limits the recombination of photogenerated electrons and holes and improves charge separation and transport. This study presents an innovative approach to enhance the charge separation efficiencies of photocathodes by implementing element doping strategies, which may contribute to further research on photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

In recent years, copper tungsten oxide (CuWO 4) has attracted increasing attention as a highly potential candidate for photoelectrochemical (PEC) water splitting, primarily because of its suitable bandgap, which enables efficient light absorption. However, challenges such as high charge recombination and poor bulk transport have resulted in low PEC performance. To address this, MXene, a novel member of two-dimensional (2D) material, was used to mitigate charge recombination by serving as a hole-transporting layer (HTL) deposited onto a CuWO 4 /FTO substrate. In this study, MXene was fabricated by interactions with different solvents, including tetramethyl ammonium hydroxide (TMAOH), hydrazine (N 2 H 4), and potassium hydroxide (KOH). The work function of MXene and interlayer spacing were adjusted via the intercalation process with various intercalant agents which changes the surface functional groups of MXene to modify the work function and increase the surface area. In addition, the generation of Schottky contact at the CuWO 4 /MXene interface could improve the charge transfer and decrease the charge recombination. The photoelectrodes synthesized in this study were thoroughly characterized using various analytical techniques, including linear sweep voltammetry, high-resolution transmission electron microscopy, electrochemical impedance spectroscopy, and ultraviolet spectroscopy. The results showed a notable improvement in the photoelectrochemical (PEC) performance of 0.35 mA/cm2 of the FTO/CuWO 4 /TMAOH-MXene/Co-Pi photoanode. The synergistic combination of CuWO 4 and MXene facilitated efficient charge transfer from CuWO 4 to the intercalated MXene and reduced electron-hole recombination. The findings suggest that MXene-modified CuWO 4 photoelectrodes hold great potential for efficient hydrogen production, thereby advancing the development of sustainable energy technology. [Display omitted] • The interlayer spacing and work function of MXene were adjusted by the intercalation agents. • The design of CuWO 4 /TMAOH-MXene/Co-Pi photoelectrode exhibited an outstanding PEC performance. • MXene acted as a hole-transporting layer and enhanced the stability of CuWO 4 photoelectrode. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) cells are regarded as a promising approach to convert sunlight to chemical fuels, whereas the serious photo‐induced charge recombination of the semiconductor photoelectrode hinders its solar conversion efficiency. Over the past few decades, designing and constructing heterojunction photoelectrodes via thermodynamically favorable charge transfer have been proven to be effective in boosting photo‐induced charge separation. However, the conventional heterojunction construction strategy generally introduces incompatible, nonconformal, or defective interfaces, leaving considerable room to improve the thermodynamically favorable charge transfer efficiency in the heterojunction photoelectrodes. To compensate for the unsatisfied charge transfer efficiency, some novel strategies, such as grain boundary engineering, band gap engineering, field‐effected engineering, etc., are adopted to provide additional charge transfer driving force, which significantly improves the charge transfer efficiency. In this review, these novel strategies are discussed beyond the conventional heterojunction construction, and the prospects for the development and applications of heterojunction photoanodes are also proposed. [ABSTRACT FROM AUTHOR]

Cu2O/TiO2 heterostructure is prepared by electrodepositing Cu2O on rutile phase TiO2 particles. The morphology, structural, and optical properties of Cu2O/TiO2 heterostructure are determined by scanning electron microscopy, Raman spectroscopy, X‐ray diffractometer, and UV–vis absorption spectrum. The Cu2O/TiO2 heterostructure photoelectrochemical‐type photodetector is constructed based on this heterostructure. Experimental results show that the photoresponsivity and visible light absorption of the Cu2O/TiO2 heterostructure are significantly enhanced compared to those of TiO2 and Cu2O which demonstrate that the Cu2O/TiO2 heterostructure with a special interfacial structure is conducive to accelerating the separation and transfer of photogenerated carriers. The photoresponsivity and photocurrent density of Cu2O/TiO2 can reach 154 μA W−1 and 15.6 μA cm−2 at 0 V. In addition, the photocurrent density of the Cu2O/TiO2 heterostructure steadily increases with the enhancement of irradiation power density. Moreover, no significant attenuation of the photocurrent density is observed in the prepared Cu2O/TiO2 heterostructure after 1800 s of photo‐on/off cycles. These results suggest that the Cu2O/TiO2 heterostructure‐based photodetector holds great potential in the photodetection field. [ABSTRACT FROM AUTHOR]

Over the past few years, the elimination of pharmaceuticals from polluted water has been a major challenge for many researchers. The presented project reports the photoelectrochemical (PEC) detection of ciprofloxacin (CIP) by using a BiVO 4 thin layer prepared by a facile spin coat method on an Indium doped tin oxide (ITO) glass as photoanode. The mesoporous nanostructure of the fabricated photoanodes was characterized with UV–vis diffusion transmission spectra, Tauc plot, electrochemical impedance spectroscopy, Mott-Schottky diagram, and chronoamperometry analysis. After optimizing some of the key factors affecting current response of the photoanode, the PEC detection results showed that the BiVO 4 thin-layer photoanode had high and stable photocurrent responses for CIP under UV-Vis light irradiation. Furthermore, the fabricated PEC sensor displayed two wide-spreading linear detection ranges from 0.05 to 100 nM and 100–5700 nM with very low detection limits (LOD) of 0.016 nM. Furthermore, the interferences evaluation demonstrated excellent selectivity of the PEC sensor toward CIP molecules in the presence of other interfering species in solution. Therefore, the marked performance of this photoelectrode in the PEC detection of CIP, extraordinary stability, and admirable reproducibility suggests its potential as a photoanode for the pharmaceutical pollutant oxidation including various antibiotics in wastewater. • Synthesized BiVO 4 material exhibited excellent PEC activity. • ITO/BiVO 4 was successfully applied for the PEC sensing of CIP residues. • This PEC sensor presented excellent performance than another PEC sensor. • The application of sensor was studied in athlete's biological samples. [ABSTRACT FROM AUTHOR]

Antibiotic residues have become a significant challenge in food safety, threatening both ecosystem integrity and human health. To combat this problem, we developed an innovative photo‐powered, self‐powered aptasensor that employs a novel carbon‐doped three‐dimensional graphitic carbon nitride (3D‐CN) combined with a metal‐organic framework composed of N‐doped copper(I) oxide‐carbon (Cu2O@C) skeletons. The 3D‐CN serves as the photoanode, offering stable photocurrent production due to its three‐dimensional open framework structure. The N‐doped Cu2O@C acts as the photocathode, providing oxidation protection for the metal core and enhancing light absorption due to its metal‐organic framework structure. A key feature of our work is exploiting the Fermi level difference between the n‐type photoanode and p‐type photocathode, which facilitates faster migration of photogenerated electrons toward the photocathode, thereby enhancing the sensor's self‐powered effect. Experimental results reveal that upon aptamer loading, the sensor can linearly detect tetracycline (TC) within a range of 0.5 pmol/L to 300 nmol/L, with a detection limit as low as 0.13 pmol/L. It also demonstrates excellent selectivity, stability, and reproducibility, making it applicable to real samples such as milk and river water. Consequently, our research provides a highly efficient and sensitive method for monitoring TC in food, with significant practical implications and profound impacts on food safety. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) technology is a promising strategy that can directly convert sunlight into chemical energy. Direct solar water splitting through the PEC process is a desirable method for green hydrogen (H2) production. This technology has also the potential to capture CO2 and convert it into fuels using sunlight and water, besides converting N2 and H2O to produce ammonia (NH3), which acts as transportable H2 storage. The cracking of NH3 to produce H2 can also be accomplished using PEC technology. Despite improved PEC performance having been shown, stability, efficiency, and scalability issues still need to be resolved. Even so, PEC technology has much potential as a clean and sustainable solution for addressing global energy and environmental challenges. [ABSTRACT FROM AUTHOR]

Efficient photoelectrochemical photodetectors based on WSe2/rGO have been fabricated using an annealing process. The initial performance enhancement of these devices was primarily attributed to the improved bandgap structure of WSe2 and the high carrier mobility of rGO, which facilitated an efficient transition of valence band electrons to the conduction band. Upon this understanding, a comparison between bulk WSe2 and WSe2 nanosheets (WSe2 NSs) was conducted. It was found that, at a bias voltage of 0.6 V, the photocurrent density of WSe2 NSs devices was 76% higher than that of similar bulk WSe2 devices, reaching 0.044 μA/cm2. Owing to the significant advantages of rGO, extensive testing of various WSe2 to rGO ratios was performed, identifying the precise composition that optimized photoelectric performance. Notably, under conditions of 0.5 M Na2SO4 electrolyte, 120 mW/cm2 irradiance, and 0.6 V bias potential, the devices achieved a photocurrent density of 0.64 μA/cm2, which is approximately 25.72 times higher than that of bulk WSe2 and 14.61 times more than WSe2 NSs. Moreover, the photoresponse trended upward with increasing irradiation intensity. Specifically, when the irradiation intensity was increased to 160 mW/cm2 and the bias voltage was raised from 0 V to 0.6 V, the photoresponsivity increased by 5.8 times, from 1 μA/W to 5.8 μA/W. The photodetectors constructed using the optimal WSe2/rGO ratio exhibited no significant performance degradation during a 4000-s cyclic on/off test, demonstrating their robustness under operational conditions. This study highlights the substantial potential of WSe2/rGO hybrids in enhancing the performance of photoelectrochemical photodetectors. [ABSTRACT FROM AUTHOR]

Over the past few years, the elimination of pharmaceuticals from polluted water has been a major challenge for many researchers. The presented project reports the photoelectrochemical (PEC) detection of ciprofloxacin (CIP) by using a BiVO4 thin layer prepared by a facile spin coat method on an Indium doped tin oxide (ITO) glass as photoanode. The mesoporous nanostructure of the fabricated photoanodes was characterized with UV–vis diffusion transmission spectra, Tauc plot, electrochemical impedance spectroscopy, Mott-Schottky diagram, and chronoamperometry analysis. After optimizing some of the key factors affecting current response of the photoanode, the PEC detection results showed that the BiVO4 thin-layer photoanode had high and stable photocurrent responses for CIP under UV-Vis light irradiation. Furthermore, the fabricated PEC sensor displayed two wide-spreading linear detection ranges from 0.05 to 100 nM and 100–5700 nM with very low detection limits (LOD) of 0.016 nM. Furthermore, the interferences evaluation demonstrated excellent selectivity of the PEC sensor toward CIP molecules in the presence of other interfering species in solution. Therefore, the marked performance of this photoelectrode in the PEC detection of CIP, extraordinary stability, and admirable reproducibility suggests its potential as a photoanode for the pharmaceutical pollutant oxidation including various antibiotics in wastewater.

Cadmium sulphide nanoparticles (CdS NPs), renowned for their tunable bandgap, exhibit significant potential for photochemical applications. A simple, green, cost-effective synthesis approach is quite desirable to harness their full potential. With this prospect, we present the green synthesis of CdS NPs using cinnamon extract as a reducing and stabilizing agent. The as-synthesized NPs were characterized with the aid of diverse characterization techniques. The optical properties and bandgap were performed using a UV–Vis spectrophotometer, which was found to be 2.91 eV. The X-ray diffraction (XRD) revealed the crystalline nature of NPs and an average crystallite size of 5 nm. The morphology and shape were analyzed by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM). The surface of synthesized NPs was found to be spherical, and some irregular-shaped NPs were observed. The bioengineered CdS NPs showed a pH of the zero charge point charge (pHZPC) of approximately 6.5 representing the NP surface charge as neutral. Further, the semiconductor properties were evaluated using photoelectrochemical (PEC) studies, demonstrating charge transport dynamics. CdS NPs exhibited efficient photocatalytic degradation of MB dye: 91% in 90 min under UV light and 94% in 70 min under sunlight. The cytotoxicity of the CdS NPs was performed against MCF-7 breast cancer cells with an IC50 value of 110 µg/mL, significantly lower than the IC50 of cisplatin which is 31.63 µg/mL. In the biological applications, CdS NPs exhibited a slight haemolytic nature at high concentrations demonstrating their biocompatibility. In the antibacterial activity of NPs, the results are moderately good. This comprehensive investigation underscores the potential as efficient photocatalysts for dye degradation and exhibiting cytotoxicity against breast cancer cells. [ABSTRACT FROM AUTHOR]