Photoelectrocatalytic Activity Research Articles

Cell-Membrane-Inspired Ultrathin Silica Nanochannels Coating for Long-Term Stable Photoelectrocatalysis with Enhanced Performance.

Photoelectrocatalysis has attracted significant attention for water splitting and contaminant degradation. However, the lifetime of photoelectrocatalysis devices is hampered by the severe instability and photocorrosion of the photo-active nanomaterial on the photoelectrode, which is a key limitation to realizing industrialization. Typically, the conventional protection strategy of photoelectrodes usually suffers from the trade-off between the photoelectrocatalytic activity and stability. Inspired by biological cell membrane with water channels, here a highly permeable and ultrathin silica coating with ultrasmall straight nanochannels is in situ grown that stabilizes the photoelectrode. These ultrasmall channels boost photoelectrocatalysis by accelerating water transport and reducing the reaction energy within the confined nanochannels. Specifically, the ultrathin coating imparts significant mechanical and structural stability to the photo-active nanomaterial, thereby preventing its detachment, dissolution, and crystal damage without compromising performance. As a result, the protected photoelectrode exhibits enhanced water splitting activity and excellent stability over 120 h, whereas the photocurrent of the unprotected photoelectrode degrades rapidly. Meanwhile, the coated photoelectrode also exhibits superior photoelectrocatalytic degradation efficiency (>97%), even after the 10th cycle. This strategy is facile and universal and can be extended to construct other stable and high-performance electrodes for promoting photoelectrocatalysis in practical applications.

Optimizations of Liquid Phase Deposition Processes for Enhanced Photoelectrocatalytic Activities of Tungsten Oxide Thin Films.

This study focuses on the preparation of tungsten oxide (WO3) as the photoanode for water oxidations by the liquid phase deposition (LPD) technique and its optimizations to improve the photoelectrochemical performance. The alternative precursor large stock solution process was achieved to simplify the LPD process for WO3 thin film preparation. The effect of boric acid in the precursor solutions on the physicochemical properties of the deposited WO3 thin films was investigated. As a result, we found that the optimized concentration of boric acid realized the highest photoelectrochemical performance. Through the optimizations of reaction conditions and surface analyses, we concluded that the preparations of a semiconductor film via the LPD technique had the potential to obtain high-performance photoelectrocatalytic applications.

Highly enhanced photoelectrocatalytic activity of NiFe/Ni/BiVO4 photoanode by a facile photoelectron-activation process in neutral solution

Photoelectrocatalytic water splitting is a promising approach to convert solar energy to hydorgen energy. Delicate design of photoanode is crucial for the excellent catalytic activity. Here, a NiFe-LDH/Ni/BiVO4 composite photoanode was prepared by magnetron sputtering of Ni followed by electrochemical deposition of NiFe-LDH on BiVO4 photoelectrode. Interestingly, after a concise photoelectron-activation process, a photocurrent of 4.9 mA/cm2 (1.23 V vs. RHE) was obtained in neutral solution, which is 4 times of the pristine BiVO4 photoanode. The photoelectro-activation process not only enhances the photocurrent, but also significantly supresses the positive spiking phenomenon of the photocurrent. A series of characterizaitons including XRD, SEM, EDX, HRTEM, and XPS ect. were performed, which revealed that the photoelectron-activation process led to the reconstruction of the surface structure of NiFe-LDH/Ni/BiVO4. The dynamic characterizaitons including stepped potential chronoamperometry, steady-state photoluminescence (PL) spectra, open-circuit potential diagrams, and electrochemical impedance spectroscopy (EIS) ect. were performed. It indicates that the activated samples can provide an enhanced internal electric field and enable the charge carriers being efficiently injected into the electrode/electrolyte interface to promote the water oxidation reaction. This investigation provided a facile activation method for BiVO4-based composite photoanode, and highly increase the PEC performance in neutral condition.

Revealing the Effect of Anion Regulation in NiCo2X4 (X = O, S, Se, Te) on Photoassisted Methanol Electrocatalytic Oxidation.

Designing nonprecious metal anode catalysts for photoassisted direct methanol fuel cells (PDMFCs) remains a challenge. As a semiconductor catalyst with a spinel structure, NiCo2O4 has good methanol catalytic oxidation activity and photocatalytic activity, making it a highly promising anode non-noble metal catalyst for PDMFCs. However, compared with the noble metal catalyst, the photoelectrocatalytic activity remained to be improved. In this report, an anion regulation strategy was adopted to improve the photoassisted methanol electrocatalytic activity. Using a CoNi-Aspartic (CoNi-Asp) nanorod as the precursor, the anion-regulated NiCo2X4 (X = O, S, Se, Te) was prepared by oxidation, sulfuration, selenization, and telluridation reactions. The regulation of anions and their effects on the electronic structure, intermediate product, and photoelectric catalytic performance of NiCo2X4 (X= O, S, Se, Te) was systematically discussed. Photoelectrochemical characterization and adsorption energy of •OH revealing the volcano-like correlation between the anion in NiCo2X4 (X = O, S, Se, Te) and their photoelectrocatalytic performance. The narrowest band gap (2.239 eV), the highest •OH adsorption energy (-3.32 eV), and the highest ratio of Co3+/Co2+ (2.19) ensure the best photoelectric catalytic performance of NiCo2S4, under the visible light irradiation, the photoresponse current density was 1.9 A g-1, the current density at 0.6 V was up to 21.9 A g-1. After 9 h of stability testing, the current retention rate was 80%. This report sheds an idea for the rational design of non-noble anode catalysts for PDMFCs.

Alternative Technique to RDE to Evaluate Photoelectrocatalysts for ORR

The scarcity of fuels due to the growing energy demand has encouraged research into topics such as energy conversion with materials that can take advantage of solar energy. Such situations have promote the emergence of various new materials to assist reactions of special interest such as oxygen reactions. (Oxygen Reduction Reaction, ORR and Oxygen Evolution Reaction, OER). Thus, numerous materials are emerging with the photoelectrocatalytic activity towards OER and ORR reactions. To evaluate the photo-assisted OER requires technical conditions that a rotating disk electrode (RDE) does not satisfy.In this work we present an alternative technique to RDE by adapting a flow in a microfluidic platform to satisfy the limit current while it can be irradiated and thus evaluate the photoelectocatalysis of a semiconductor that has the characteristic of a photoelectrocatalyst.To make the comparison, a glassy carbon electrode (GCE) was used using the Pt/C system in a three-electrode cell designed with a microfluidic channel where we found that the mass flow is comparable to rpm.

Synthesis of H2O2 to Self-Catalyzed Generation of •OH over ZnO/CuI/Cu Foam Electrode for the Self-Fenton Cleaning of Wastewater.

A novel ZnO/CuI/Cu foam electrode was constructed, which demonstrated excellent photoelectrocatalytic activity for the self-Fenton degradation of tetracycline in water. The H2O2 yield was 405.0 μmol L-1 over ZnO/CuI/Cu foam (CIZ-3) under light irradiation (100 mW cm-2) for 5 h at -1.23 V (vs NHE), which was 1.7 times higher than that of ZnO/Cu foam and 1.6 times higher than that of CuI/Cu foam, respectively. The 99.0% of tetracycline was degraded by CIZ-3 due to its efficient yield of H2O2 to self-catalyzed generation of •OH. The results of the open-circuit potential between CuI and ZnO displayed that the electrons from the conduction band of CuI flowed to ZnO and the holes from the valence band of ZnO migrated to CuI. As a result, the photogenerated electron-hole pairs of ZnO/CuI were efficiently separated, which greatly promoted the photoelectrocatalytic activity of ZnO/CuI/foam. The toxicity of the aqueous tetracycline solution was significantly reduced by observing the growth of Escherichia coli in the treated wastewater.

Enhanced photoelectrocatalytic performance of direct Z-scheme CuWO4|TiO2 heterojunction for moxifloxacin oxidation

Films formed by the heterojunction of CuWO4 and TiO2 on conductive transparent substrate (fluorine-doped tin oxide - FTO) were utilized in moxifloxacin (MOX) degradation under polychromatic irradiation. The individual materials and the heterojunctions were systematically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), confirming the formation of heterojunctions from pure materials. Compared to the other configuration, the electrochemical characterizations showed higher photocurrent for FTO|CuWO4|TiO2 heterojunction, associated with better charge transport in the film. Thus, the photocatalytic activity of the FTO|CuWO4|TiO2 heterojunction was investigated for MOX degradation, which achieved an oxidation of 54.4 % of the drug in 150 min, employing the configuration electrochemically assisted heterogeneous photocatalysis (EHP). The efficiency of the heterojunction is about 2.5 times greater than that shown by electrodes formed from their individual materials. Radical scavenger studies showed that •OH radicals are the main species responsible for MOX oxidation process. The results of XPS, radical scavenging, photoelectrochemical, and photoelectrocatalytic activity show a charge transfer mechanism associated with a direct Z-scheme and that the FTO|CuWO4|TiO2 film is promising for the degradation of organic pollutants.

Charge Redistribution in Nise2/Mos2 n–n Heterojunction Towards the Photoelectrocatalytic Degradation of Ciprofloxacin

AbstractThis study reports the photoelectrocatalytic (PEC) activity of a n–n heterojunction comprising MoS2 and NiSe2. The synthesis of the composite was achieved through a facile solvothermal method, yielding an exfoliated MoS2 layered sheet loaded with NiSe2 nanoparticles. Under visible light radiation and an external electric field, the obtained composite NiSe2/MoS2 exhibited enhanced catalytic activity for ciprofloxacin (CIP) degradation. The NiSe2/MoS2 heterojunction achieved about 78 % degradation efficiency with a first‐order kinetic rate of 0.0111 min−1, compared to 38 % efficiency and a first‐order kinetic rate of 0.0044 min−1 observed for MoS2. The NiSe2/MoS2 heterojunction was more advantageous due to the synergy of charge carrier induction by visible light radiation and improved charge carrier separation induced by the external electric field. The formation of n–n heterojunction at the interface of the two materials resulted in charge redistribution in the materials, with a simultaneous realignment of the band structure to achieve Fermi energy equilibration. The primary reactive species responsible for CIP degradation was identified as the photo‐induced h+. Furthermore, the catalyst exhibited high stability and reusability, with no significant reduction in activity observed after five experimental cycles. This study reveals the potential of exploring the synergy between the photocatalytic and electrocatalytic processes in removing harmful pharmaceutical compounds from water.

Partial Photoelectrocatalytic Oxidation of 3‐Methylpiridine in Green Conditions by Nanotube/Nanowire Ti/TiO2 Plates Prepared in Aqueous, Glycerol, or Ethylene Glycol Medium

AbstractNanotube/nanowire structured TiO2 samples on Ti plates were prepared by anodic oxidation in aqueous, glycerol or ethylene glycol medium under different experimental conditions and characterized by XRD, SEM‐EDX, electrochemical methods (photocurrent profiles and electrochemical impedance spectroscopy). The nanostructured TiO2 was built on relatively large Ti plates, and consequently, in some preparation conditions, different morphologic properties were observed in the underside and upside zones of the electrodes, especially in ethylene glycol medium. The electrodes were tested for selective photoelectrocatalytic oxidation of 3‐methylpyridine to 3‐pyridinemethanol, 3‐pyridinemethanal and vitamin B3 in water under UVA irradiation. The best performance was found with the electrode prepared in ethylene glycol/water/NH4F (98/2/0.3 w/w) medium at 36 V potential for 3 h, while the worst was that prepared in aqueous medium which showed the shortest nanostructure length. Unlike photoelectrocatalysis and photocatalysis, no aromatic alcohol/carbonyl products were obtained in electrocatalytic and photolytic experiments. The selectivity values of the products were similar for the various electrodes, while the morphology of the nanotubes/nanowires and their quantity which affects the total active surface area were essential for the substrate conversion. The results also show that the photocurrent intensity, XRD peak intensity, and electrical conductivity are correlated with photoelectrocatalytic activity of the Ti/TiO2 electrodes.

Synthesis of TiO2 nanoplate decorated by Co particles immobilized on porous Polycalix[4]resorcinarene for enhancing photocatalytic degradation of drug acetaminophen by light Emitting Diode

The sustainability and feasibility of using visible irradiation in photocatalysis is a promising approach for water purification. In this study, photocatalytic degradation of a widely used analgesic and antipyretic drug, acetaminophen (ACM), with metal-loaded an efficient photocatalyst (TiO2NPs-Co/Polycalix (Christen et al., 2010) [4]resorcinarene (TCP)) was inv estigated using visible light. photocatalyst structural, surface, and morphological features were characterized using FTIR, XRD, TEM, EDX, PL, and DRS analyses. Considering various sites of Polycalix (Christen et al., 2010) [4]resorcinarene in the TCP, studied by trapping experiments. A novel charge transfer bridge for electron-hole recombination is made possible by using Co and TiO2 as electron transfer mediators with electronic conductivity. This results in efficient process and energy optimization, which makes it easier for ACM to degrade throughout the absorption process. The ACM (15 and 40 mg/L) achieved complete degradation under visible light irradiation with 0.6 g/L of TCP at pH = 5.0 during 120 min reaction because of the good synergetic effect of the catalyst systems. Additionally, the intermediates generated by photo electrocatalytic activities were identified, and two potential paths for degradation were suggested. Some of these organic products were identified by High-Performance Liquid Chromatography (HPLC).

Optimization of light response and electron redistribution of active sites by structuring CoS2/MoS2/Ni3S2 heterojunction for highly efficient photo-assisted oxygen evolution

Highly efficient photoelectrocatalysts become one of the current research hotspots for overall water splitting, the design of heterojunctions with a wide response range to sunlight and efficient separation and migration of photo-generated carriers is challenging. Herein, a nanorod CoS2/MoS2/Ni3S2 photoelectrocatalyst with heterojunction is prepared by a one-step hydrothermal method. Under simulated solar irradiation, CoS2/MoS2/Ni3S2 exhibits excellent photoelectrocatalytic activity for OER, with overpotential of 166 mV and the cell voltage of 1.464 V at 10 mA cm−2, and the catalytic performance exhibited a slight decline after 12 hours of stable operation. In addition the STH efficiency reaches 6.6 %. Experiments and DFT calculations demonstrate that CoS2 as a photoactive layer optimizes the light absorption properties of catalyst. Additionally, MoS2 as a co-catalyst modulates the d-band centers and the electronic structure of Co active site, reducing the energy barrier of the rate-determining step. Meanwhile, the II-type heterojunction formed by CoS2 and MoS2 can effectively promote the separation and migration of photo-generated carriers, which further enhances the photoelectrocatalytic OER performance. This work provides a novel insight to design photoelectrocatalysts with transition metal sulfide heterojunction for overall water splitting.

Fabrication of piezotronic ZnO p-n homojunction via metal/oxygen defects modulation for efficient photoelectrocatalysis

Homojunction is a viable alternative strategy to realize excellent charge separation for enhancing photoelectrocatalytic performance. However, the feasible regulation of the homojunction interface remains challenging. Herein, a ZnO n-p homojunction with the piezotronic effect is constructed via an in-situ solvothermal method for enhancing photoelectrocatalytic activity. ZnO nanorods are transformed from n-type to p-type ZnO nanoparticles with zinc vacancies, leading to the n-p homojunction. The optimal NPZ-36 exhibits a superior photocurrent density of 1.56 mA/cm2 at 1.23 V vs. RHE and a high incident photon to current conversion efficiency of 75 % at 360 nm. Impressively, with the merits of inherent piezoelectric and photocatalytic properties of wurtzite ZnO, the piezoelectric-enhanced photoelectrochemical activity originates from the simultaneous promotion of bulk charge transfer and interfacial charge separation in ZnO n-p homojunction. The photocurrent density of NPZ-36–900 can reach to 2.02 mA/cm2 under the stirring rate of 900 rpm, which is 2.1 times higher than that of pure ZnO photoanode.

Boosting photoelectrocatalytic oxygen evolution activity of BiVO4 photoanodes via caffeic acid bridged to NiFeOOH

Bismuth vanadate (BiVO4) is a promising n-type photoanode material for photoelectrochemical (PEC) water splitting. However, its activity is impeded by poor charge carrier transport and sluggish oxygen evolution kinetics. In this study, we reports a Fe doping and caffeic acid (CA)/NiFeOOH (NiFe) modification with BiVO4 photoanode (NiFe/CA/Fe-BiVO4) to enhance the PEC water oxidation performance and stability. The modified BiVO4 demonstrates significant advantages in promoting the PEC performance and stability. Specifically, Fe doping via in-situ electro-deposition results in smaller crystal sizes, larger specific surface areas, and more exposed active sites. Furthermore, co-catalyst NiFe connects with Fe-BiVO4 through CA bridge facilitates a more uniform self-assembly distribution of NiFe on BiVO4 surface. The NiFe/CA/Fe-BiVO4 exhibits an excellent photocurrent density of 6.2 mA/cm2 at 1.23 VRHEand demonstrates good stability at 0.8 VRHE. In addition, the composite photoanode shows a high applied bias photon-to-current efficiency (ABPE) value of 2.15% at 0.65 VRHE. EPR and in-situ FTIR confirm the generation of superoxide active species (O2- and ·O2-) during the PEC water oxidation reaction.

Nanozyme-coupled photoelectrocatalytic system based on peroxidase-mimetic BiOI cathode and WO3 photoanode for efficient degradation of 3-chlorophenol

As an advanced oxidation technology, solar light-driven photoelectrocatalysis has been considered to be a sustainable method for wastewater treatment. Meanwhile, peroxidase-mimetic nanozymes have emerged as a promising tool for environmental remediation. In this work, we aimed to combine nanozyme catalysis with solar light-driven photoelectrocatalysis to achieve efficient degradation of persistent contaminant, using 3-chlorophenol (3-CP) as the representative pollutant. In the designed system, WO3 nanoplate photoanode displayed high photoelectrocatalytic activity for both 3-CP degradation and H2O2 production under simulated solar light. Furthermore, peroxidase-like BiOI with nanoflower structure was immobilized on hydrophobic carbon cathode to catalyze the oxidation of 3-CP by in situ generated H2O2. The constructed nanozyme-coupled photoelectrocatalytic system exhibited a satisfactory 3-CP degradation efficiency of 91.1 % after 90-min treatment. In addition, the possible reaction mechanisms and degradation pathways of 3-CP in such a system were discussed.

Photoelectrocatalytic and photocorrosion behavior of MoS2- and rGO-containing TiO2 bilayer photocatalyst immobilized by plasma electrolytic oxidation

TiO2-based bilayer photocatalysts including MoS2 light-absorbing and rGO conductive layers were immobilized on titanium supports using the plasma electrolytic oxidation process. Their properties were studied to find out the photoelectrocatalytic activity and photocorrosion stability. Investigating the immobilization process revealed that the formation of the bilayer structure increased the photocatalyst's surface porosity, thickness, and roughness. The preparation of the MoS2/TiO2 and rGO/TiO2 layers synergistically enhanced the light-harvesting capability of the photocatalyst in the visible region and slowed down the recombination of the photoinduced charge carriers. The bilayer photocatalyst improved the photoelectrodegradation kinetics of methylene blue pollutant by 1.6 times under 100 W xenon irradiation and 5 V applied bias. Evaluating the photocorrosion stability in sulfate medium by potentiodynamic polarization and electrochemical impedance spectroscopic analysis confirmed that the polarization resistance of the bilayer photocatalyst improved by 4.5 and 3.8 times compared to the pure TiO2 photocatalyst under dark and xenon light, respectively. Moreover, the Mott-Schottky experiment denoted that the corrosive ion adsorption was reduced in the bilayer photocatalyst.

Rod-like BiVO4 with two-phase structure to boost photoelectrocatalytic degradation activity for tetracycline via the p-n junction

Bismuth vanadate (BiVO4) as a potential photoanode is widely applied in photoelectrocatalytic (PEC) degradation flied. However, it is inhibited due to easy recombination of the photogenerated carries. Herein, rod-like morphology BiVO4 with monoclinic and tetragonal phase structure (R-BVO) are prepared using hydrothermal approach. Density functional theory (DFT) calculation confirms that the build-in electron field is constituted at contact interface of two-phase structure. Benefiting from the one-dimensional conduction of rod like morphology and the p-n junction formed by two-phase structure, R-BVO indicates outstanding photocurrent, the applied bias photo-to-current efficiency (ABPE) and the incident photoelectron conversion efficiency (IPCE). Compared with the single phase structure particle BiVO4 (P-BVO), the PEC degradation rate for TC of R-BVO is 96.4 %, which is 1.4 times of P-BVO. Equally importantly, the Ni foam is used as conducting substrate owing to its low cost and practicability, moreover, it is not only easy to determine catalyst dosage, but also ensures the tight contact between active substance and substrate, preventing the catalyst from peeling off in reaction. This study puts forward an adventurous strategy for designing effective photoanode materials.

Fabrication of WO3 nanorod arrays modified by BiOBr and their enhanced photoelectrocatalytic activity

BiOBr/WO3 nanorod array (NRA) composite photoelectrodes were successfully prepared using a solvothermal method. The instrumental characterisation of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, incident photoelectric conversion efficiency and ultraviolet diffuse reflectance indicates that the obtained BiOBr/WO3 NRAs exhibit good crystallinity and purity, and they can utilise light with wavelengths less than approximately 440 nm. On the surface of the WO3 nanorods, BiOBr thin nanosheets grow uniformly with strong adhesion and a 3D structure. The composite photoelectrode loaded with an appropriate amount of BiOBr (labelled BW-1 NRA) exhibits the best photoelectrocatalytic (PEC) activity. The PEC degradation efficiency of 10 mg/L of bisphenol A reached 95.7 % after 3 h at 1.0 V bias voltage. This value is 2.8 times that of individual photocatalytic degradation. After four times of recycling, the decrease in catalytic activity is insignificant, indicating the good stability of the catalyst. By analysing the results of the photoelectrochemical properties, band structures and types of free radicals, a conclusion is drawn that the excellent catalytic performance of BW-1 NRA is ascribed to the following aspects. (1) The formation of the p–n heterojunction by BiOBr and WO3 can effectively separate photogenerated electrons and holes. (2) Bias drives the migration of photogenerated electrons to the external circuit, further preventing the recombination of photogenerated electrons and holes. (3) The 3D structure of the photoelectrode has a large specific surface area and multiple active sites, improving light absorption and utilisation efficiency.

Photo-electro concerted catalysis of a highly active Pt/CoP/C nanocomposite for the hydrogen evolution reaction

A facile phosphorus doping method was used to synthesize Pt/CoP/C exhibiting superior photo electro-catalytic activity toward HER, and H2 amount reaches 5384.18 mmol h−1 g−1 under irradiation, displaying a cost-effective catalytic capacity of Pt.

Straightforward electrochemical synthesis of a Co3O4 nanopetal/ZnO nanoplate p-n junction for photoelectrochemical water splitting.

Hydrogen production through photoelectrochemical (PEC) reactions is an innovative and promising approach to producing clean energy. The PEC working electrode of a Co3O4/ZnO-based p-n heterojunction was prepared by a straightforward electrochemical deposition with different deposition times onto an FTO (Fluorine-doped Tin Oxide) glass substrate. The successful synthesis of the materials was confirmed through analysis using XRD, FTIR, SEM-EDX, DRS, and PL techniques. Mott-Schottky plots and some characterization studies also checked the determination of the formation of the p-n junction. Co3O4/ZnO/FTO with a Co3O4 deposition time of 2 minutes exhibited the lowest onset potential of 0.82 V and the lowest overpotential of 470 mV at a current density of 10 mA cm -2. Furthermore, the photo-conversion efficiency of the Co3O4/ZnO/FTO sample showed 1.4 times higher current density than the ZnO/FTO sample. A mechanism is also proposed to enhance the Co3O4/ZnO/FTO electrode photo-electrocatalytic activity involved in the water-splitting reaction. The Co3O4/ZnO/FTO electrode shows significant potential as a promising PEC electrode to produce hydrogen.

Synergistic enhancement of photoelectrocatalytic activity and photostability in CdS photoanodes by ultrathin polydopamine layer

CdS-based photocatalyst and photoanode have recently drawn the attention of several investigators primarily in connection with its excellent visible light response in various catalytic reactions involving light, especially photoelectrochemical (PEC) water splitting. The present approach highlights the concept of constructing a biological functional layer incorporated for photochemical instable semiconductors for practical PEC applications. However, practical applications of CdS-based photoanodes are limited by rapid charge recombination and severe photo corrosion. This study introduces a novel approach to enhance reaction kinetics and stability. We present a CdS nanorod photoanode with an ultrathin layer of polydopamine (PDA), prepared through a conformal polymerization assembly process, which serves as a robust platform for subsequent assembly of hole cocatalysts FeOOH. The resulting sandwich structure of CdS/PDA/FeOOH photoanode demonstrates an incident to current efficiency (IPCE) of 7.1% at 420 nm and a photocurrent of 1.9 mA/cm2 at 1.23 V versus the reversible hydrogen potential (RHE). The integrated photoanode exhibits significantly prolonged photostability compared to CdS, CdS/PDA, and CdS/FeOOH photoanodes. The significance of this work lies in constructing a FeOOH structure (with hole extraction and consumption capabilities) on the CdS outermost layer using an easy-to-operate preparation process, thereby revealing the ability of PDA to enable the passage of photogenerated holes. The present approach highlights the concept of integrating biologically functional layers to stabilize photochemically unstable semiconductors for practical PEC applications.