Photoelectrochemical Efficiency Research Articles

Anchoring group regulation in semiconductor/molecular complex hybrid photoelectrode for photoelectrochemical water splitting

AbstractRational interface engineering via regulating the anchoring groups between molecular catalysts and light‐absorbing semiconductors is essential and emergent to stabilize the semiconductor/molecular complex interaction and facilitate the photocarriers transport, thus realizing highly active and stable photoelectrochemical (PEC) water splitting. In this mini review, following a showcasing of the fundamental details of hybrid PEC systems containing semiconductor photoelectrodes and molecular catalysts for water splitting, the state‐of‐the‐art progress of anchoring group regulation at semiconductor/molecular complex interface for efficient and stable PEC water splitting, as well as its effect on charge transfer kinetics, are comprehensively reviewed. Finally, potential research directions aimed at building high‐efficiency hybrid PEC water splitting systems are summarized.

Solution Process–Based Facile Flame–Boosted Low‐Valence Transition Metal Doping on Pristine Oxide for Highly Enhanced Photoelectrochemical Solar Water Oxidation Reaction

ABSTRACTAs for the high sustainable solar hydrogen production via water splitting, transition metal doping on an oxide photoanode in photoelectrochemical (PEC) cells has been recognized as an effective approach. However, conventional thermal‐diffusion‐mediated doping strategies face the challenge of resolving sluggish catalytic kinetics for oxygen evolution reaction (OER) and its practical utilization for the synthesis of photoanode films. Herein, we introduce facile ultrafast flame‐boosted doping of Mo into a BiVO4 (FL MoBVO) film for 20 s to achieve an efficient PEC OER. Mo elements in a low‐valence state (i.e., Mo6−δ) and Mo6+ are successfully doped into the photoanode, which manipulate the energy band structure, facilitating the downward shift of band edges and promoting the surface catalytic kinetics. Consequently, the flame‐boosted Mo‐doping results in superior PEC performance in a mild environment with neutral electrolyte without introducing any other additives or co‐catalysts, where the photocurrent density at 1.23 VRHE under 1 sun illumination in pH 7 is outstandingly enhanced, over 9‐fold higher than that of a pristine BiVO4. The flame‐boosted doping induces significantly enhanced photoexcited charge transport and catalytic reaction kinetics performances simultaneously. Our report provides the effective strategy boosting both the thermodynamic and kinetic charge migration properties for sustainable materials.

Photoelectrochemical immunosensor for chloramphenicol detection based on cation exchange reaction-mediacted photocurrent enhancement of ZnIn2S4/TiO2/Ti3C2 MXene coupled with controlled-release strategy.

Aphotocurrent enhancing photoelectrochemical (PEC) immunosensor was developedfor 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 enhancingthe 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 1pg/mL to 50ng/mL, and the detection limit was 0.24pg/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 thephotocarrier. 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 determinationof CAP.

Toward Efficient Utilization of Photogenerated Charge Carriers in Photoelectrochemical Systems: Engineering Strategies from the Atomic Level to Configuration.

Photoelectrochemical (PEC) systems are essential for solar energy conversion, addressing critical energy and environmental issues. However, the low efficiency in utilizing photogenerated charge carriers significantly limits overall energy conversion. Consequently, there is a growing focus on developing strategies to enhance photoelectrode performance. This review systematically explores recent advancements in PEC system modifications, spanning from atomic and nanoscopic levels to configuration engineering. We delve into the relationships between PEC structures, intrinsic properties, kinetics of photogenerated charge carriers, and their utilization. Additionally, we propose future directions and perspectives for developing more efficient PEC systems, offering valuable insights into potential innovations in the field.

Unveiling Morphology-Structure Interplay on Hydrothermal WO3 Nanoplatelets for Photoelectrochemical Solar Water Splitting.

Photoelectrochemical (PEC) water splitting offers a sustainable route for hydrogen production, leveraging noncritical semiconductor materials. This study introduces a seed layer-free hydrothermal synthesis approach for semiconductor photoanodes based on tungsten trioxide (WO3) nanoplatelets. Aiming to boost the efficiency of photoelectrochemical water splitting through optimization of the synthesis parameters of bare WO3, focusing on temperature, time, and layer thickness, we systematically explored their effects on the morphological, structural, and optical characteristics of WO3 photoanodes. Combining a low-temperature regime (90 °C for 12 h) with a multilayer strategy (up to six-layers) resulted in significant improvements in photocurrent. Particularly, the five-layer sample exhibited a remarkable increase of over 70% compared to the single-layer photoanode. Morphological aspects, particularly the fractal dimension of nanoplatelets and the emergence of the (220) crystalline orientation, usually neglected, were found to play pivotal roles in modulating the PEC response. Rietveld refinement of X-ray diffraction patterns further underscored the importance of crystallographic facets, volume unit cell expansion, and microstrain in influencing photocurrent outcomes. Furthermore, we adapted the Mott-Schottky equation to incorporate the fractal dimension reflecting the nanostructures' nature, usually set to a planar interface. Our findings highlight the interchange between nanoplatelet morphology and structural parameters in determining the PEC efficiency of WO3 photoanodes.

Phenyl-C61-butyric acid methyl ester (PCBM) nanoparticle mediated boasting of photoelectrochemical and photocatalytic properties of bismuth vanadate/lead sulphide (BiVO4/PbS) composite thin-film

This work delineates the fabrication and characterization of BiVO4/PbS and BiVO4/PCBM/PbS-based composite heterostructure for visible-light-driven applications, such as pollution remediation, photoelectrochemistry (PEC), and applied bias to photoelectrochemical hydrogen generation efficiency (ABPE). The heterostructured composite was synthesized by a combination of Spin coating (for bismuth vanadate - BiVO4 thin film fabrication and PCBM deposition), and Successive Ionic Layer Absorption and Reaction -SILAR (for lead sulphide - PbS deposition) method and characterized using UV–visible Spectroscopy, time-resolved photoluminescence spectroscopy (TRPL), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and photoelectrochemistry (PEC) analysis (PEC). The key benefit of incorporation of PCBM nanoparticles in BiVO4/PCBM/PbS was realized through 1) ∼ 70 % improvement in the photocurrent density during electrochemistry analysis, 2) ∼ 2.3 times enhancement in ABPE, and 3) ∼ 43 % enhancements in ‘rate constant’ towards photocatalytic (methylene blue) degradation compared to BiVO4/PbS. The work shows the benefits of the PCBM-conductive carbon-based electron transport layer as a bridge between two inorganic semiconductors (BiVO4 and PbS) towards enhancing fast electron separation and transport at the interface during visible light irradiation.

Highly efficient Z-scheme CeO2/Bi2MoO6 heterojunction strengthened by redox mediator for photoelectrochemical detection of tetracycline with enhanced sensitivity

Accurate monitoring of antibiotics that pose risks to the environment and human health is essential. The photoelectrochemical system has emerged as a rapid and precise method for detecting environmental pollutants. However, current photoelectrochemical materials made of semiconductors face challenges due to poor photoelectric conversion efficiency. In this study, a Z-scheme CeO2/Bi2MoO6 heterojunction structure was successfully prepared by a cost-effective hydrothermal method. By leveraging built-in electric field and the Ce3+/Ce4+ redox mediator, this heterojunction achieved high photoelectrochemical conversion efficiency and functioned effectively as a sensor for tetracycline (TCH). The designed sensor demonstrated two linear ranges of 0.05–100 nM and 100–300 nM with an ultra-low detection limit of 15.4 pM for TCH. Additionally, the sensor exhibited excellent selectivity and high stability, demonstrating its potential for TCH detection in tap-water and milk samples. This study presents a simple and reliable method for the practical detection of antibiotic residues in environmental and food samples.

Accelerating charge separation in p-n heterojunction photocathode for photoelectrochemical oxygen reduction and evolution in photo-enhanced zinc-air battery

For the first time, we constructed a band-matched ZnO/NiO staggered p-n heterojunction photoelectrochemical (PEC) catalyst with superior charge separation and transfer efficiency to optimize the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics demands of a photo-enhanced zinc-air battery (PZAB). The ingenious design of heterojunction architecture effectively stimulates an internal self-built electric field (BEF), thus accelerating charge separation and migration during PEC catalysis. Upon illumination, the photocathode not only endows a promoted PEC catalytic competence to drive ORR and OER, but also reduces the charge–discharge voltage gap of PZAB. Density functional theory (DFT) calculations further disentangled the PEC catalysis activity origins by substantiating the strongly decreased Gibbs free energy potently for generating the essential intermediates *OH and *OOH during ORR and OER, respectively, and visualized the charge densities in photocathode to illustrate the authentic separation of photogenerated carriers. Remarkably, our work experimentally and theoretically sheds lights on engineering innovative and efficient bifunctional PEC catalysts to drive PZABs with photo-enhancement.

Creating an intermediate energy band to boost the photoelectrochemical efficiency of TiO2 for solar-driven hydrogen production

The utilization of photoelectrochemical processes for hydrogen generation from water and solar energy offers a promising avenue to replace non-renewable energy sources. Nevertheless, achieving high-performance photoanode electrodes poses a significant challenge. In this study, we present the synthesis cerium and chromium-doped TiO2 (CeCrTiO2) is produced through a simple, scalable, and cost-effective hydrothermal method on a fluorine-doped tin oxide (FTO) substrate. the introduction of Ce and Cr impurities is highlighted for its role in creating an impurity band within CeCrTiO2. This impurity band is instrumental in enhancing the separation and movement of electrons and holes, contributing to the improved performance of CeCrTiO2 as a photoanode in photoelectrochemical applications. Hence, the photocurrent density value of CeCrTiO2 is 4.5 times higher than that of bare TiO2. This suggests that CeCrTiO2 exhibits improved efficiency in generating a photocurrent when exposed to light, indicating enhanced photoelectrochemical performance. The amount of hydrogen produced by CeCrTiO2 is noted to be 4.88 times greater than that of bare TiO2. This highlights the material's effectiveness in harnessing solar energy to drive the water-splitting reaction, leading to a higher yield of hydrogen gas. The synthesis of CeCrTiO2 through a hydrothermal method results in a photoanode with significantly enhanced performance, positioning it as a promising candidate for advancing photoelectrochemical processes aimed at replacing non-renewable energy sources.

Photoelectrochemical Hydrogen Production from Water Using Copper‐based Chalcopyrite Thin Films

AbstractCopper (Cu)‐based chalcopyrite compounds are promising photoabsorber materials not only for solar cells but also for photoelectrochemical (PEC) systems for conversion of sunlight energy into chemical energy. PEC water splitting to generate hydrogen (H2) is one of the most advanced technologies in a PEC system for the use of Cu‐based chalcopyrite compounds. In this review, we firstly introduce crystallographic/energetic structures of Cu‐based chalcopyrite compounds in view of their applications to PEC water splitting. Explanations for the operation of PEC water splitting using semiconductor materials are then overviewed. Based on these backgrounds, studies on PEC H2 evolution over photocathodes based on CuInS2 and CuGaSe2 thin films that we have developed are reviewed in detail. For realizing efficient PEC H2 evolution over these thin films, surface modifications with an n‐type layer such as CdS and a catalytic site such as Pt deposit were found to be indispensable. Precise controls of p‐n heterointerfaces formed by introducing an n‐type layer should also be required to enhance PEC performance. Although PEC water splitting has not reached the required efficiency to be useful, effective combinations of appropriate surface and interface modifications should lead to further improvements of properties to be close to practical applications.

Photoelectrochemical sensor based on copper tetraamino phthalocyanine graphene oxide covalent compound for sensitive detection of cefazolin sodium

In the present research, a novel photoelectrochemical (PEC) sensor was built to detect cefazolin sodium. A copper tetraamino phthalocyanine (CuTAPc) covalently linked graphene oxide compound (CuTAPc-GO) was fabricated successfully by covalent bonding of CuTAPc with graphene oxide (GO). The novel PEC sensing platform was prepared using CuTAPc-GO as a photoelectric material. The prepared PEC sensor showed a higher PEC efficiency under red light. In the perfect conditions, the PEC sensor exhibited a linear correlation in detecting cefazolin sodium concentrations between 0.25 and 12.5 μM, featuring a detection limit at 0.15 μM. Furthermore, the manufacturing sensor was employed to detect cefazolin sodium in a real-world sample, demonstrating commendable sensitivity and stability. Thus, our study provides a new method for cefazolin sodium detection.

Epitaxial Growth of a Three-Dimensional Hollow and Chestnut Shell Photothermal p-n Junction Photoanode.

The p-n junction, a widely studied semiconductor material structure, offers only limited improvements in photoelectrochemical (PEC) efficiency. Herein, a three-dimensional (3D) p-n junction h-Ta3N5@CoN featuring a stable chestnut shell hollow sphere structure and photothermal effect was synthesized by using an epitaxial growth strategy. The fine fibers within the sphere induce Rayleigh scattering, which scatters unabsorbed light, thereby enabling secondary absorption and enhancing light utilization. The quantum confinement effects generated by CoN fine fibers, which are sized in a few nanometers, inhibit the recombination of electron-hole pairs. Moreover, the lattice matching between Ta3N5 and CoN allows for smoother movement of carriers and nonradiative relaxation phonons along the lattice, thereby enhancing the transport of both carriers and heat. The obtained h-Ta3N5@CoN/FTO p-n junction photoanode, under near-infrared (NIR) auxiliary irradiation, demonstrates a photocurrent of 8.71 mA cm-2 at 1.23 VRHE. Moreover, the h-Ta3N5@CoN+NIR/FTO photoanode can sustain operation for 168 h, which, to my knowledge, surpasses the operational durations of all other Ta3N5-based photoanodes. This study synthesizes three-dimensional hollow chestnut shell photothermal p-n heterojunctions through an epitaxial growth strategy, endowing the material with a more efficient carrier separation and photothermal transfer efficiency.

Well-matched dual photoelectrodes regulated cathodic photoelectrochemical aptasensing capability: Elucidating the role of photoanode in enhancing the sensing signal

To screen well-matched photoelectrodes is highly desirable for achieving efficient signal amplification of the dual-photoelectrode photoelectrochemical (PEC) system. However, the role of photoanode in the characteristic signal amplification remains unclear. In this study, an integrated PEC system was developed by employing well-matched ZnIn2S4/Bi2S3 photoanode and BiOBr-Au nanoparticles (NPs) photocathode. ZnIn2S4/Bi2S3 with super light-harvesting property and Z-scheme electron transfer pathway, served as the photoanode to continuously inject electrons into the photocathode under visible light, resulted in a 69 times enhanced photocurrent signal than that of conventional PEC system. More importantly, a systematic discussion of photoanode in enhancing the sensing signal was presented through the experimental measurements of Mott-Schottky and open-circuit voltage. Using ofloxacin (OFL) as a model target, an aptasensor was constructed for its potential sensing applications, and the possible reaction mechanism of OFL were also conducted. The proposed aptasensor demonstrated the capability to detect concentrations of OFL ranging from 0.1 pM to 5 nM, achieving a detection limit of 47 fM (S/N = 3). Moreover, the aptasensing platform exhibited advantages of high sensitivity, good anti-interference and repeatability. This study proposed insights in understanding the role of photoanode for designing more efficient dual-photoelectrode PEC aptasensors for precise monitoring of other environmental pollutants.

Bicontinuous nickel/tin oxide films with enhanced photoelectrochemical hydrogen production efficiency

Self-assembled bicontinuous NiO:SnO2 films are proposed for enhanced photoelectrochemical hydrogen production efficiency due to their high interface-to-volume ratio and three-dimensional interconnectivity. The X-ray diffraction confirms the superior crystallinity of the bicontinuous NiO:SnO2 films. Bicontinuous NiO:SnO2 films reveal a heterostructure of mixed NiO and SnO2 phases, where the NiO phase exhibits the distribution of small grains, whereas the SnO2 phase exhibits large agglomerates of SnO2 crystals embedded in the NiO structure. The bicontinuous NiO:SnO2 films exhibit lower bandgap energy and higher electrical conductivity compared to pure NiO and pure SnO2 films. The photoresponsivity of the bicontinuous oxide films is higher than pure NiO and pure SnO2 films. These results imply the presence of strong charge interactions at the three-dimensional interfaces in bicontinuous NiO:SnO2 films. The hydrogen revolution reaction analysis confirms that the bicontinuous NiO:SnO2 films exhibit higher photoelectrocatalyst hydrogen production activity compared to pure NiO and pure SnO2 films.

Effect of the deposition temperature on ZnCd(SSe)2 for enhance the efficiency of solar cell application

The photoelectrochemical efficiency of ZnCd(SSe)2 thin films shows a notable enhancement, increasing from 0.08 % to 0.28 %, when deposited at different temperatures (room temperature, 40 °C, 50 °C, and 60 °C). This study aims to develop ZnCd(SSe)2 thin films using a cost-effective single-step process called the Arrested Precipitation Technique (APT). This study demonstrates that varying the deposition temperatures significantly impacts the optical, structural, and morphological properties of the resulting thin films. Optical analysis shows a reduction in the optical energy band gap from 1.92 to 1.63 eV as the bath temperature increases. X-ray diffraction confirms the formation of nanocrystalline thin film samples with improved crystallinity, as indicated by the increased intensity of the (100) diffraction peak. Scanning electron microscopy reveals changes in surface morphology corresponding to different deposition temperatures. The thin films exhibit polycrystalline characteristics, as verified by transmission electron microscopy and selected area electron diffraction pattern analysis. Energy Dispersive Spectroscopy analysis identifies the presence of Cd, Zn, S, and Se elements with near-ideal stoichiometry, suggesting a favorable composition. Importantly, the photoelectrochemical performance increases significantly from 0.08 % to 0.28 % with rising deposition temperature, marking a substantial improvement with potential for further investigation and development in the field.

Non-radical photoelectrochemical production of free chlorine from diluted chloride solutions on BiVO4

Free chlorine (FC) species are important oxidants for organic synthesis and environmental remediation. However, due to competitive water oxidation, it’s hard to obtain satisfied photoelectrochemical Faradic efficiency (FE) of FC via energetically unfavorable •Cl intermediate. Herein, we developed a non-radical strategy to realize efficient and stable FC production. High FE (86.2 %), high partial photocurrent density (2.8 mA/cm2) and excellent stability were achieved even under the conditions of diluted Cl (0.1 M) and neutral pH. Furthermore, compared with BVO, BVO@AgCl exhibited multi-fold faster rates for chlorine-mediated oxidations of styrene and arsenite with superior FEs (90.0 % vs. 59.4 %; 89.3 % vs. 47.3 %). Mechanistically, photogenerated holes are accumulated at AgCl sites (Cl+). FC is catalytically produced from the nucleophilic attack of Cl to Cl+, which bypasses •Cl intermediate and energetically outcompetes water oxidation. This work provides promising photoelectrochemical systems for highly efficient and stable production of FC, promoting high-value-added chemical synthesis and water treatment.

Enhanced Photoelectrochemical Water Splitting Using NiMoO4/BiVO4/Sn-Doped WO3 Double Heterojunction Photoanodes.

Efficient photoelectrochemical (PEC) water splitting systems in photoelectrodes are primarily challenged by electron-hole pair recombination. Constructing a heterostructure is an effective strategy to overcome this issue and to enhance PEC efficiency. In this study, we integrated NiMoO4, known for its proper electrocatalytic conductivity, into a BiVO4/Sn-doped WO3 heterojunction using solution-based hydrothermal and spin-coating methods, forming an innovative double heterojunction concept. The resulting NiMoO4/BiVO4/Sn:WO3 triple-layer heterojunction photoanode exhibits a photocurrent density of 2.06 mA cm-2 in a potassium borate buffer (KBi) electrolyte at 1.23 V vs RHE, outperforming the bilayer BiVO4/Sn:WO3 heterojunction (1.45 mA cm-2) and Sn:WO3 photoanodes (0.55 mA cm-2) by approximately 1.4 and 3.7 times, respectively. Remarkably, the NiMoO4/BiVO4/Sn:WO3 double heterojunction photoanode exhibits notable stability, showing only an approximate 30% reduction in initial photocurrent density after 10 h of measurement in the KBi electrolyte without a hole scavenger. This stability is attributed to the excellent corrosion resistance of the thin NiMoO4 layer, effectively protecting the bilayer BiVO4/Sn:WO3 heterojunction photoanode from photocorrosion. Our findings show how this novel double heterojunction, established through simple and cost-effective solution-based methods, offers a promising approach to enhancing PEC water splitting applications.

Sensitization of AgInS2 nanoparticles enhances photoelectrochemical water splitting performance of CeO2 nanosheet arrays photoanode

In this study, we present a promising CeO2/AgInS2 heterostructure photoanode for photoelectrochemical (PEC) water decomposition. Mott-Schottky analysis is employed to confirm the formation of a type-II heterostructure between AgInS2 nanoparticles and CeO2 nanosheet arrays (NSAs) fabricated through electrochemical deposition and successive ionic layer adsorption and reaction. Electrochemical impedance spectroscopy, photoluminescence analysis, and Bode diagram spectroscopy confirm the effective charge carrier separation and significantly prolonged the charge lifetime of the CeO2/AgInS2 heterojunction photoanode. Consequently, the maximum photocurrent density of the constructed CeO2/AgInS2 photoanode relative to Ag/AgCl under zero bias test conditions is 69.8 times higher than the pure CeO2 NSAs. Additionally, the charge transfer mechanism is further verified by the calculated work function and differential charge density of CeO2/AgInS2 heterojunction. This study provides a valuable reference for the synthesis and preparation of heterojunction photoanode for efficient PEC water decomposition.

Mechanism Exploration of the Photoelectrochemical Immunoassay for the Integration of Radical Generation with Self-Quenching.

Photoelectrochemical (PEC) sensing mechanisms based on enzyme-catalyzed strategies primarily achieve the quantitative analysis of biomolecules through the enhancement or attenuation of photocurrent signals. However, there are still no reports that delve into the principles of photocurrent signaling conversion in the reaction between photoactive materials and the biomolecules. In this work, we demonstrated that indium oxysulfide InOS-0.5 heterojunction has excellent peroxidase activity to catalyze the reaction of H2O2-generated hydroxyl radicals (•OH) with the self-generated electrons, thereby resulting in synergistic quenching of the photocurrent signal. Based on the above principles, we coupled InOS-0.5 with a sandwich-type immunoassay to introduce H2O2 production catalyzed by glucose oxidase for the development of a PEC immunosensing platform. H2O2 reacted with InOS-0.5 to produce •OH with strong oxidizing properties, thus quenching the photogenerated electrons and realizing the PEC detection of the carcinoembryonic antigen (CEA, as a model analyte). The photocurrent intensity decreases with the logarithmic increase in CEA concentration (0.02-50 ng mL-1), with a remarkable limit of detection of 8.9 pg mL-1 (S/N = 3). This study further investigates the mechanism of hydrogen peroxide-induced photocurrent quenching, providing deeper insights into the mechanisms of electron-hole transport in hollow porous semiconductor materials and paving the way for the development of efficient PEC sensors.

Enhanced Electrochemical Performance of Tin Oxide Quantum Dots on Reduced Graphene Oxide under Light.

The study utilized a simple and cost-effective approach to improve the photoelectrochemical (PEC) water-splitting performance of various materials, including reduced graphene oxide (rGO), tin oxide nanostructures (SnO2), and rGO/SnO2 composites. The composites examined were rS15, containing 15 mg of rGO and 45 mg of SnO2, and rS5, with 5 mg of rGO and 50 mg of SnO2, tested in a sodium hydroxide (NaOH) electrolyte. Notably, the rS5 electrode showed a significant increase in PEC efficiency in 0.1 M NaOH, achieving a peak photocurrent density of 13.24 mA cm-2 under illumination, which was seven times higher than that of pristine rGO nanostructures. This enhancement was attributed to the synergistic effects of the heterostructure, which reduced resistance and minimized charge recombination, thereby maximizing the catalytic activity across the various electrochemical applications. Furthermore, the rS5 anode demonstrated improved Tafel parameters, indicating faster reaction kinetics and lower overpotential for efficient current generation. These results highlight the potential for optimizing nanostructures to significantly enhance PEC performance, paving the way for advancements in sustainable water-splitting technologies.