Photocatalytic Fuel Cell Research Articles

Retraction of "Enhanced Electricity Generation and H2O2 Production in a Photocatalytic Fuel Cell and Fenton Hybrid System Assisted with Reverse Electrodialysis".

[This retracts the article DOI: 10.1021/acsomega.9b00282.].

Visible‐Light‐Responsive TiO2/NiFe Mixed Metal Oxide‐Carbon Photocatalytic Fuel Cell with Synchronous Hydrogen Peroxide Production

AbstractThe photocatalytic fuel cell (PFC) synergistically utilizes the photocatalytic oxidation of biomass and the electrochemical reaction of the fuel cell to selectively reduce oxygen to produce hydrogen peroxide (H2O2) at room temperature. Herein, we report a PEC system that NiFe‐layered double oxide (LDO)/TiO2 as photoanode, carbon black as cathode for utilizing biomass and oxygen to simultaneously convert solar energy into electricity and produce hydrogen peroxide without applied electric bias. The photoanode catalyst was fabricated with TiO2‐supported NiFe mixed metal oxides (MMO) which obtained by layered double hydroxides (LDHs) pyrolysis. The research results indicate that under solar irradiation, the photocurrent density and faraday efficiency have a significantly improved compared with pure NiO/TiO2. With methanol as the feeding fuel at the photoanode, the optimal device yields an excellent open circuit voltage (Voc), short circuit current (Jsc) and a maximum power density (Pmax) of 0.78 V, 1093 μA/cm2 and 169 μW/cm2, respectively. This performance improvement is attributed to the Fe3+ doped in NiFe‐MMO and use TiO2 as an electron transport layer. Simultaneously, the hydrogen peroxide concentration reached 0.443 mM after 180 min illumination at the cathode, the generation rate was optimized to 0.126 μmol/min/cm2 at neutral aqueous solution. The PEC system exhibited an excellent higher rate of production for H2O2, and faraday efficiency (FE) reached 31.7 %. This PFC is a green technology for photocatalytically oxidize biomass at the photoanode and convert solar energy into electricity as well as supply it to the cathode to reduce O2 to produce H2O2 efficiently.

A highly efficient NiFe-layer double hydroxide/TiO2 heterojunction photoanode-based high-performance bifunctional photocatalytic fuel cell

A NiFe-LDH/TiO2 heterojunction photoanode is employed to improve photocatalytic degradation and electricity output of the dual-photoelectrode photocatalytic fuel cell (PFC) for the first time. Incorporation of NiFe-LDH can extend the optical response range, accelerate reaction kinetics, and enhance the electrocatalytic efficiency of the photoanode. The (NiFe)1:1-LDH/TiO2 photoanode possesses an extraordinary photocatalytic activity, and the photocurrent density achieved 1.85 mA cm-2 at 1.6 V vs. RHE with 1 M KOH solution, meanwhile, it was higher than over 1.5 times of the pure TiO2. Cuprous oxide is used as an ideal photocathode material in the PFC system. The photoelectricity conversion and photocatalysis degradation performance in degrading azo dye, glucose, and phenol as model organic waste have been entirely recorded under 1 sun illumination. The actual maximum power density of the proposed PFC was 0.206 mW cm-2 in degrading glucose over 150 min period. The azo dye removal of MB using the NiFe-LDH/TiO2 and pure TiO2 photoanode-based PFC was 94.6% and 80.5%, respectively. The prominent PFC activity shows that the proposed PFC could be used in organic wastewater treatment and energy conversion.

Z-scheme MoO3 anchored-hexagonal rod like ZnO/Zn photoanode for effective wastewater treatment, copper reduction accompanied with electricity production in sunlight-powered photocatalytic fuel cell

This study presents a sunlight-powered photocatalytic fuel cell (PFC) which can directly produce electricity with synchronized oxidative degradation of organics and reductive treatment of copper ion (Cu2+). MoO3/ZnO/Zn fabricated by facile wet-chemical and impregnation procedures is used as a photoanode in a dual-chamber system. The optimized PFC with a maximum power density of 0.007 mW cm−2, an open circuit voltage of 835 mV and a short circuit current density of 0.082 mA cm−2 can be achieved at 200 mg L−1 initial Cu2+ concentration at solution pH 3. Under these conditions, more electron-hole pairs were separated on the photoanode for phenol oxidation, and the electrons were transferred to the cathode for Cu2+ reduction. About 89.5% chemical oxygen demand (COD) of 40 mg L−1 initial phenol concentration was removed, while 93.5% removal efficiency for 200 mg L−1 initial Cu2+ concentration can be reached within 240 min. The ameliorated photoelectrochemical performance could be owing to the Z-scheme MoO3/ZnO heterojunction that can extend optical absorption and facilitated charge separation according to the optical and electronic analyses. The stable cyclic operation of this PFC was achieved. For the real plating wastewater treatment, the COD removal of phenol, Cu2+ reduction and maximum power density output were 73.6%, 85.0% and 0.005 mW cm−2, respectively.

Enzyme-based biofuel cells for biosensors and in vivo power supply

Biofuel cells (BFCs) are energy conversion devices using biocatalysts to convert biochemical energy into electric energy. According to different catalysts, they can be divided into microbial fuel cells (MBFCs), enzyme biofuel cells (EBFCs), organelle biofuel cells (OBFCs), and photocatalytic fuel cells (PFCs). Compared with traditional fuel cells, EBFCs can provide sustainable energy under mild conditions such as physiological temperatures and near-neutral media, which have attracted extensive attention in the field of medical implants, drug pumps, biosensors and other devices. Enzyme load capacity and electron transfer rate are the key issues affecting the performance of EBFCs. Immobilization of enzyme on conductive materials with high specific surface area and good biocompatibility can effectively solve the bottleneck problems of EBFCs in actual applications such as low power density and short service life. This paper summarizes common biological enzymes of EBFCs and their immobilization methods, and emphasizes the breakthrough of nanomaterials, such as carbon nanomaterials, metal nanomaterials and composites in the fields of EBFCs. In addition, the application, challenges, and prospects of the EBFCs in the future development direction are also proposed.

Solar Energy Conversion and Storage Using a Photocatalytic Fuel Cell Combined with a Supercapacitor

This work studies the production of electricity by a photocatalytic fuel cell and its storage in a supercapacitor. We propose a simple construction, where a third electrode bearing activated carbon is added to the device to form a supercapacitor electrode in combination with the supporting electrolyte of the cell. The photocatalytic fuel cell is based on a CdS-sensitized mesoporous TiO2 photoanode and an air cathode bearing only nanoparticulate carbon as an oxygen reduction electrocatalyst.

Highly-efficient degradation of organic pollutants and synchronous electricity generation in a photocatalytic fuel cell based on the catalytic reactions of hydroxyl and chlorine radicals

Organic compounds in wastewater are significant energy sources. Given this situation, a novel and high-performance photocatalytic fuel cell (PFC) integrated with NaOCl/Cu (II) was successfully constructed to effectively convert hazardous organics into clean energy. This designed system is comprised of nickel oxide (NiO)/TiO2 nanotubes (TNTs) photoanode and polyaniline (PANI)/multi-walled carbon nanotubes (MWCNTs) cathode. Compared to the single PFC, the combined system exhibited better performance. This coupled PFC/NaOCl/Cu (II) system enhanced the photocatalytic reaction and strengthened the reaction range of reactive species from the surface of electrodes to the whole liquid phase via generation of reactive chlorine radicals (Cl•, Cl2•–, ClO•) and reactive oxygen species (HO•, •O2–, HO2•). Hence, PFC/NaOCl/Cu (II) exhibited excellent cell efficiency, increasing the AB113 degradation by 48.1% and electrical power generation by 59.38% compared to the PFC system without adding NaOCl/Cu (II). The effects of the important operating parameters (initial pH, NaOCl/Cu (II), and concentration of substrate) on the PFC performance were investigated by response surface methodology (RSM). The results showed that the different model compounds could be used as fuel. The highest short circuit current density of 3.1 mA cm –2, and maximum power density of 1.12 mW cm–2 were obtained using citric acid as the substrate. This study provided an efficient approach to dispose of organic waste and to generate synchronous electrical power.

Optimization of photocatalytic fuel cells (PFCs) in the treatment of diluted palm oil mill effluent (POME)

Photocatalytic fuel cells (PFCs) are considered an advanced technology in wastewater treatment as they are able to remove organic based wastewater by using the principle of advanced oxidation processes (AOPs) and at the same time generate electricity. Despite PFCs being used to treat different types of organic based wastewater efficiently, the use of PFCs in palm oil mill effluent (POME) is still considered rare. Hence, the present research was carried out to determine the optimal conditions of contact time, pH, initial organic concentration and light intensity in order to remove the organic matter present in diluted POME. Our PFC system was constructed by using NaCl as the supporting electrolyte with ZnO/Zn as the photoanode and platinum wire as the cathode. The chemical oxygen demand (COD) removal efficiency and the amount of electricity generated was monitored in different optimization experiments using a conventional fluorescence light source. Under optimal conditions, the COD removal efficiency increased from 7% to 74 %, while the power density output also increased from 1.73 to 35.85 μW/cm2. The PFC was found to work optimally at pH 7 with a light intensity of 1300 lx for 6 h. Meanwhile, the scanning electron microscope (SEM) images revealed the high organic matter concentration in POME can lead to the deposition of an organic layer on the photoanode surface which subsequently reduced the COD removal efficiency to 17.4 %. This result has indicated that PFC is not suitable for treating the fresh POME directly from the mill, but it is more suitable for treating POME, from the last biological treatment pond.

Highly-active, metal-free, carbon-based ORR cathode for efficient organics removal and electricity generation in a PFC system

A highly-active, metal-free, carbon-based oxygen reduction reaction (ORR) cathode, i.e., graphitized N-doped carbon felt (GNCF), was prepared, for the first time, by in-situ modifying the doping species of polyacrylonitrile (PAN)-based carbon felt (CF) via a facile annealing process in Ar atmosphere. It was applied for dramatically enhanced organics degradation and electricity generation in a photocatalytic fuel cell (PFC) system. The GNCF showed enhanced specific surface area, improved graphitization and raised ratio of graphitic N, therefore resulting in excellently improved ORR performance compared to the CF. When applying the GNCF as a cathode in a PFC system, the proposed PFC showed significant improvement in degrading various model organic contaminants and outputing electricity simultaneously when compared with the PFC with CF. For instance, the apparent rate constant and electricity output efficiency showed ∼10.6 times and ∼7.2 times, respectively, improvement when using rhodamine B as model waste. Further improved performance was also achieved by aeration of air or O2 due to the further enhanced ORR. The proposed PFC was also efficient in a wide pH, and kept outstanding stability in long-term utilization.

A hybrid photocatalytic fuel cell integrated electro-Fenton system for Amaranth dye degradation and electricity generation

A dual-chambered hybrid system of photocatalytic fuel cell (PFC) and electro-Fenton (EF) process has become an emerging sustainable green approach for organic pollutant degradation and electricity generation. This hybrid system of PFC and EF (PFC-EF hybrid system) is an integration of two popular organic pollutants treatment methods, PFC and EF process. The double-cathodes configuration of PFC-EF hybrid system enhanced the oxygen reduction reaction reactivity in both PFC and EF. PFC-EF hybrid system with double cathodes achieved colour removal efficiencies of 86.2% and 84.7% in PFC and EF. Power density of 1.2211 μW cm−2 was obtained in this PFC-EF hybrid system. Results revealed that this PFC-EF hybrid system was effective in the Amaranth dye degradation and power production simultaneously.

Exploring the Effect of KOH Activated Carbon Felt Cathodes in a Sustainable Photocatalytic Fuel Cell Integrated Photo-Electro-Fenton Hybrid System

Exploring the Effect of KOH Activated Carbon Felt Cathodes in a Sustainable Photocatalytic Fuel Cell Integrated Photo-Electro-Fenton Hybrid System

Photoassisted chemical energy conversion into electricity using a sulfite‑iron photocatalytic fuel cell

Abstract Photocatalytic fuel cells (PFC) are light-assisted devices that convert chemical energy into electricity. However, conventional PFC produces extremely low photocurrents due to the slow kinetics of the photoanodes to oxidized organic fuels, thus limiting the power generation. Here, an all-inorganic PFC manufactured with heterostructured W-BiVO4/V2O5 photoanode separated from a platinum cathode by a porous membrane is described. Sulfite ions are used as a fuel anolyte and Fe3+ is the catholyte. Under lighting, the W-BiVO4/V2O5 photoanode is exceptionally efficient for oxidizing sulfite to sulfate, which results in a high photocurrent output. Under optimized conditions, the W-BiVO4/V2O5-Pt cell produces a high short-circuit current of 8.79 mA cm−2, an open-circuit potential 0.85 V, and a power density of 1.89 mW cm−2 at 4.30 mA cm−2. The excellent PFC performance is attributed to the photovoltage generated by W-BiVO4/sulfite-sulfate liquid-junctions and efficient charge separation and hole transport in the photoanode bulk promoted by the W-BiVO4/V2O5 junctions. Also, the kinetics of redox reactions are fast, eliminating the use of cocatalysts. Thus, this simple PFC concept can be a viable alternative for electricity generation.

BiVO4@PDA/TiO2/Ti photoanode with polydopamine as electron transfer mediator for efficient visible-light driven photocatalytic fuel cell

In order to enhance the electron transmission rate of photocatalytic fuel cell (PFC), BiVO4@PDA-wt% composite was successfully prepared by hydrothermal synthesis and chemical polymerization method, and used to modify TiO2/Ti to obtain BiVO4@PDA/TiO2/Ti photoanode with high efficient visible light-response. The structure, morphology, optical and photoelectrochemical properties of BiVO4@PDA/TiO2/Ti photoanode were characterized and explored. BiVO4@PDA-10 %/TiO2/Ti obtained the maximum photocurrent density of 10.68 mA cm−2 at 1.0 V (vs. SCE) under visible light illumination, which was 4.7 times that of BiVO4/TiO2/Ti. This is because of its extended π-conjugated electron system, PDA can significantly promote the charge transfer between BiVO4 and TiO2. Therefore, the separation of photogenerated electrons and holes in space can be realized, thereby the recombination of photogenerated electron-hole pairs can be reduced and ultimately the photocatalytic performance can be enhanced. With BiVO4@PDA-10 %/TiO2/Ti photoanode and Cu2O/Cu cathode, the visible-light responsive PFC exhibited high organics degradation and electricity conversion performance. Its photocurrent density, maximum power density and Rhodamine B degradation efficiency were 0.42 mA cm−2, 58.55μW cm−2 and 97.28 %, respectively.

Visible-light photocatalytic fuel cell with BiVO4/UiO-66/TiO2/Ti photoanode efficient degradation of Rhodamine B and stable generation of electricity

In order to improve the light utilization and electron transfer efficiency of the PFC system, an efficient BiVO4/UiO-66/TiO2/Ti photoanode with visible-light response was prepared by a simple sol–gel method and a hydrothermal synthesis method. The photocurrent density of the BiVO4/UiO-66/TiO2/Ti was 0.72 mA/cm2 at 0.6 V (vs. SCE) under visible light, which was 2.4 times that of BiVO4/TiO2/Ti photoanode, indicating UiO-66 used as the electron transmission medium between TiO2 and BiVO4 could enhance the electron transmission efficiency. With BiVO4/UiO-66/TiO2/Ti photoanode and Cu2O/Cu cathode, the visible-light responsive photocatalytic fuel cell (PFC) exhibited high organics degradation and electricity conversion performance. The short circuit photocurrent density (Jsc), maximum power output and degradation efficiency of Rhodamine B were 0.23 mA·cm−2, 29.26 μW·cm−2 and 91.50% in 2 h, respectively.

Core-shell BiVO4@Polythiophene co-modified TiO2 as an efficient photoanode for visible-light responsive photocatalytic fuel cell

Abstract In order to improve the utilization of visible light and enhance the electron transmission rate of photocatalytic fuel cell (PFC), core-shell BiVO4@PTh-wt% composite was successfully prepared by hydrothermal synthesis and chemical polymerization method, and used to modify TiO2/Ti to obtain BiVO4@PTh-wt%/TiO2/Ti photoanode with high efficient visible light-response. BiVO4@PTh-8%/TiO2/Ti obtained the maximum photocurrent density of 8.14 mA cm−2 at 1.0 V (vs. SCE) under visible light illumination, which was 3.59 times higher than that of BiVO4/TiO2/Ti. This can be explained by that the existence of π conjugated system in PTh helps the delocalization of π electrons which leads to high conducting properties of photoanode. With BiVO4@PTh-8%/TiO2/Ti photoanode and Cu2O/Cu cathode, the visible-light responsive PFC exhibited high organics degradation and electricity conversion performance. The short circuit photocurrent density (Jsc), maximum power output and degradation efficiency of Rhodamine B were 0.48 mA cm−2, 59.70 μW cm−2 and 96.89%, respectively.

Comparison of Different Cathode Materials for Degradation of Reactive Red 120 and Electricity Generation in Photocatalytic Fuel Cell

In this study, a photocatalytic fuel cell (PFC) based on immobilized zinc oxide (ZnO) on carbon felt photoanode and activated carbon flakes as cathode was designed for the treatment of azo dye, reactive red 120 (RR120) containing wastewater and simultaneous electricity generation. Under light irradiation, generated electron-hole pairs at the photoanode travel via the external circuit to the cathode, thus generating electricity. This was the first attempt where activated carbon flakes were applied as cathode material in PFC. This study examined the influence of parameters such as light irradiation, cathode material, initial dye concentration, supporting electrolytes, pH and concentration of oxidizing agent and hydrogen peroxide (H2O2) on the efficiency of PFC to degrade azo dye of RR120 while generating electricity. Complete decolourization of up to 50 mg/L of RR120 dye was achieved but increased dye concentration significantly reduced the PFC efficiency. The PFC efficiency improved using an amalgamation of supporting electrolytes, pH and oxidizing agent at optimum levels, achieving total dye removal and producing a maximum power density of 18.58 mW/cm2.

The construction and performance of photocatalytic-fuel-cell with Fe-MoS2/reduced graphene oxide@carbon fiber cloth and ZnFe2O4/Ag/Ag3VO4@carbon felt as photo electrodes

Photo electrodes based on conductive carbon materials are prepared via hydrothermal loadings of Fe-MoS2/reduced graphene oxide (rGO, 300 W Xe) or ZnFe2O4/Ag/Ag3VO4 (9 W LED light). The photo electrodes are used in developing a promising and attractive photo-catalytic fuel cell (PFC) that can realize simultaneous pollutant degradation, power output and hydrogen generation. The photo electrodes were characterized using scanning electron microscope (SEM), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectrophotometry (UV-Vis) and electrochemical analysis (LSV, CV, I-t). The degradation removal of Methyl orange (MO, 10 mg L−1) or berberine (BBR, 10 mg L−1) in a formic acid solution often used for hydrogen generation can reach ~98.2% and ~90.1% after 2 h irradiation in PFC, with a cell voltage of ~400 mV and hydrogen generation at ~0.025 μmol cm−2. Presence of formic acid promotes degradation of MO and BBR, while the presence of MO or BBR affects hydrogen generation adversely. The bias over the two photo electrodes drives the transfer of electrons from ZnFe2O4/Ag/Ag3VO4 to the Fe-MoS2/rGO and protons capture the electrons to form hydrogen. The holes and reactive oxidative species (ROS) oxidize the organics. This reduced the recombination of photo-induced carriers, thus improved the pollutant removal and hydrogen evolution.

Progress on catalytic electrodes and fuel cell systems for industrial wastewater treatment

Industrial wastewater containing dyes, antibiotics, heavy metal ions and other refractory organic pollutants has complicated components and poor biodegradability. Comparing to traditional bio-treatment processes, electrochemical technologies have significant advantage in treating such kinds of wastewater due to the electrochemically generated reactive species. Modifying the electrodes with catalytic components can enhance pollutant removal capacity in electro-catalytic (EC) or photo-electro-catalytic (PEC) integrated systems, but high energy consumption of electricity still restricts their implement. Self-biased fuel cells, including photocatalytic fuel cells (PFCs) and microbial fuel cells (MFCs), are more sustainable in industrial wastewater/pollutants treatment. Highly active catalytic electrodes are essential to promote pollutant removal and energy conservation. This article reviews the recent development of novel catalytic electrodes in preparation, optimization and sustainable application for industrial wastewater treatment. Technical advantages and optimization spaces of fuel-cell integrated systems (based on PFCs and MFCs) are introduced, and their challenges in large-scale application are pointed out. Catalytic electrodes have broader application fields than powder-form catalysts due to the easy-recyclability and the synergy of catalysis and electrochemistry. An ideal catalytic electrode should be conductive, highly (photo-)electro-active, physically and chemically stable, easy to prepare and low-cost. By optimizing the preparation/loading of novel catalytic materials (heterojunctions, single-atom catalysts etc.), various catalytic electrodes, in forms of self-standing (metal-based, carbon-based and others), film/membrane and particles, etc., can be obtained with extraordinary (photo-)electro-catalytic activity. Innovative design of catalytic electrodes in structure and component may in-situ integrate multiple technologies such as (photo-)electro-catalysis, advanced oxidation processes (AOPs) and membrane filtration, etc., which provides more possibility for enhancing electrochemical systems. Novel catalytic electrode of low-cost and high efficiency is still desirable for further optimization of integrated electrochemical systems. PFCs convert solar energy into electricity from the wastes (fuels). Various PFCs (single or dual photo-electrode(s)) have been developed for the degradation of dyes, antibiotics and other refractory pollutants. The electricity generation of novel PFC has been improved to 1 V (open circuit voltage) or more in some cases. Enhanced pollutant degradation and energy recovery by optimizing the function of electrode and structure of PFCs are still desirable for complex wastewater treatment. By using exoelectrogens, highly-active catalytic electrodes (anode and/or cathode) can be applied in MFC integrated systems to promote the degradation of refractory pollutants. The synergy of bacteria and catalytic electrodes broadens the application of bio-processes in industrial wastewater treatment, and also benefits the energy recovery (electricity, hydrogen, heavy metals, etc.) of systems. Innovative designs of systems are expected to further reduce the operating costs from ion-exchange membrane, light irradiation and aeration. Although pollutant removal and energy conservation of fuel cells can be further improved by integrating AOPs (Fenton process, sulfate or chlorine radical advanced oxidation, etc.) or combining other processes (EC, PEC, desalination, etc.), less chemical consumption and simpler system configuration/operation are the main trends of sustainable and cleaner production. In the future, efforts need to be done for large-scale industrial wastewater treatment by fuel cell systems: (1) Develop novel catalytic electrodes of low-cost with enhanced performance (visible light response) and integrated functions (photo- and/or electro-catalysis, filtration, AOPs, etc.). (2) Construct novel integrated fuel cell systems with highly active catalytic electrodes for multiple pollutant control and energy recovery. (3) Optimize large-scale preparation of catalytic electrodes, and simplify the operations of fuel cell systems, for energy-efficient and cost-effective treatment of real industrial wastewater, during long-term run.

A highly sustainable hydrothermal synthesized MnO2 as cathodic catalyst in solar photocatalytic fuel cell

A unidirectional flow solar photocatalytic fuel cell (PFC) was successfully developed for the first time to offer alternative for electricity generation and simultaneous wastewater treatment. This study was focused on the synthesis of α-, δ- and β-MnO2 by wet chemical hydrothermal method for application as the cathodic catalyst in PFC. The crystallographic evolution was performed by varying the ratios of KMnO4 to MnSO4. The mechanism of the PFC with the MnO2/C as cathode was also discussed. Results showed that the catalytic activity of MnO2/C cathode was mainly predominated by their crystallographic structures which included Mn–O bond strength and tunnel size, following order of α- > δ- > β-MnO2/C. Interestingly, it was discovered that the specific surface areas (SBET) of different crystal phases did not give an impact on the PFC performance. However, the Pmax could be significantly influenced by the micropore surface area (Smicro) in the comparison among α-MnO2. Furthermore, the morphological transformation carried out by altering the hydrothermal duration demonstrated that the nanowire α-M3(24 h)/C with 1:1 ratio of KMnO4 and MnSO4 yielded excellent PFC performance with a Pmax of 2.8680 μW cm−2 and the lowest Rint of 700 Ω.

A highly efficient photocatalytic methanol fuel cell based on non-noble metal photoelectrodes: Study on its energy band engineering via experimental and density functional theory method

Photocatalytic fuel cell (PFC) is considered as a new energy source due to its cooperative conversion capacity of both solar energy and chemical energy. In this work, a highly efficient ZnO/BiVO4 photoanode is synthesized on fluorine-doped tin oxide (FTO) by continuous electrodeposition and hydrothermal method. Then, a visible-light driven dual photoelectrode photocatalytic methanol fuel cell (PMFC) consisted of the ZnO/BiVO4 photoanode and Cu2O photocathode is designed and constructed. Electrochemical results show that the short-circuit current density (Jsc), the open-circuit voltage (Voc) and the maximum power output (Pmax) of the prepared PMFC can reach 5.18 mA/cm2, 0.82 V and 0.91 mW/cm2 under simulated solar irradiation, respectively. Surface photovoltage (SPV) transients reveal the charge transporting dynamics in semiconductor heterojunction, and photoelectrochemical experiments further confirmed the light-induced methanol oxidation and oxygen reduction process. Under illumination, an interior potential difference between n-type ZnO/BiVO4 and p-type Cu2O actuate the electrons on the photoanode to transfer through the external circuit to photocathode, combining with the holes and generating electricity. The built-in electric field from the ZnO (002) surface to the BiVO4 (001) surface is confirmed based on the theoretical calculation of density functional theory (DFT).