Photocurrent Production Research Articles

A self-powered photoelectrochemical aptasensor using 3D-carbon nitride and carbon-based metal-organic frameworks for high-sensitivity detection of tetracycline in milk and water.

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 0.5pmol/L to 300nmol/L, with a detection limit as low as 0.13pmol/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.

A cathodic photoelectrochemical self-powered aptasensor for ratiometric detection of cortisol based on PCN-224@graphene nanocomposites

Cathodic photoelectrochemical (PEC) sensors have garnered considerable research interest in bioanalysis for their ability to mitigate interference from photogenerated holes in concomitant reducing substances, but there remains a challenge to improve detection accuracy with rational strategies. In this study, a ratiometric assay was developed for cathodic PEC aptasensing of cortisol (COR), a stress hormone. Under visible-light exposure, porphyrin-based metal organic framework (PCN-224) and poly(diallyldimethylammonium chloride)-modified reduced graphene oxide (PrGO) composites were utilized as photoactive materials, enabling cathodic photocurrent production at 0 V. The spatially resolved dual photocathodes were combined with a COR-binding aptamer to selectively recognize the COR target, with one serving as the control. The ratio of the concentration-dependent inhibited photocurrent response (PI1) to the reference signal (PI2) from the control photocathode was employed for the sensitive COR bioassay. The proposed aptasensor revealed a broad linear range toward COR concentration from 0.4 nM to 800 nM, with a detection limit (3S/N) of 0.14 nM. The proposed sensor was successfully applied to real human serum samples, demonstrating promise in detecting disease markers in medical diagnostics.

Bacterial-Polyhydroxybutyrate for Biocompatible Microbial Electrodes

The development of bioelectrochemical systems requires careful selection of both their biotic and abiotic components to obtain sustainable devices. Herein, we report a biophotoelectrode obtained with polyhydroxybutyrate (PHB), a biopolymer, which purple non-sulphur bacteria produce as an energy stock under specific environmental conditions. The electrode was obtained by casting a mixture composed of PHB and carbon fibers in a 3:2 mass ratio. Following, the composite material was modified with polydopamine and thermally treated to obtain a hydrophilic electrode with improved electrochemical behavior. The bio-based electrode was tested with metabolically active cells of Rhodobacter capsulatus embedded in a biohybrid matrix of polydopamine. The system achieved enhanced catalytic activity under illumination, with an 18-fold increase in photocurrent production compared to biophotoelectrodes based on glassy carbon, reaching a current density of 12 ± 3 μA cm−2, after 30 min of light exposure at +0.32 V. The presented biocompatible electrode provides a sustainable alternative to metal-based and critical raw material-based electrodes for bioelectrochemical systems.

Ideal Structures of Isolated BiVO4 Nanoparticles on WO3 Nanocorals to Enhance Photoelectrochemical Hydrogen Evolution

Metal oxide nanoparticles (NPs) of n-type semiconductors have recently garnered significant attention in the photoelectrochemical (PEC) field. In this study, isolated BiVO4 NPs on anodized WO3 nanocorals are investigated with respect to the formation mechanism of the NPs and the correlation between particle size and PEC efficiency. The sizes and distances of the BiVO4 NPs on the WO3 nanocorals are controlled via spin-coating and heat-treatment. The optimized BiVO4 NPs, with ideal sizes of 10 nm and distances of 100 nm between them, exhibit satisfactory electron and hole diffusion lengths, suppressing electron–hole recombination and promoting the exposure of WO3 to ultraviolet light. Furthermore, high-quality BiVO4, without the formation of by-products due to the optimized concentrations of Bi and V in the precursor solution, results in a 2.3-fold higher photocurrent density and H2 production, and a 6-fold higher incident photon-to-current conversion efficiency (IPCE) compared to those of pristine WO3 nanocorals.

Exploring photoexcited spin states for fullerene-derivatives based organic bulk heterojunction solar cells using magneto-photocurrent

Fullerene-derivatives based bulk heterojunctions hold an exceptionally important role on the roadmap of highly efficient organic solar cells (OSCs). In recent years, the utilization of the non-fused ring acceptors based OSCs has further improved photovoltaic power conversion efficiencies. Among these, one of the fundamental issues is to explore and to understand the spin-related polaron dissociation at charge transfer states because they act as the central unit for the photovoltaic action. It is also eagerly important to quantify some internal fields, such as hyperfine fields and the spin–orbit coupling. The aim of the work is to develop a method for unraveling the photoexcited spin states, particularly for the fullerene-derivative based OSC. Furthermore, it helps to elucidate a long-standing issue regarding the relatively high production of photocurrent for the P3HT:PC71BM system, which is indeed contrary to its counterpart the P3HT:PC61BM system. Their corresponding Jablonski diagrams have been determined in order to understand interior spin dynamics. The method of the study offers an alternative route for an understanding of device performance from the spin-related aspect.

Increased solar-driven chemical transformations through surface-induced benzoperylene aggregation in dye-sensitized photoanodes

The impact of benzo[ghi]perylenetriimide (BPTI) dye aggregation on the performance of photoelectrochemical devices was explored, through imide-substitution with either alkyl (BPTI-A, 2-ethylpropyl) or bulky aryl (BPTI-B, 2,6-diisopropylphenyl) moieties, to, respectively, enable or suppress aggregation. While both dyes demonstrated similar monomeric optoelectronic properties in solution, adsorption onto mesoporous SnO2 revealed different behavior, with BPTI-A forming aggregates via π-stacking and BPTI-B demonstrating reduced aggregation in the solid state. BPTI photoanodes were tested in dye-sensitized solar cells (DSSCs) before application to dye-sensitized photoelectrochemical cells (DSPECs) for Br2 production (a strong oxidant) coupled to H2 generation (a solar fuel). BPTI-A demonstrated a twofold higher dye loading of the SnO2 surface than BPTI-B, resulting in a fivefold enhancement to both photocurrent and Br2 production. The enhanced output of the photoelectrochemical systems (with respect to dye loading) was attributed to both J- and H- aggregation phenomena in BPTI-A photoanodes that lead to improved light harvesting. Our investigation provides a strategy to exploit self-assembly via aggregation to improve molecular light-harvesting and charge separation properties that can be directly applied to dye-sensitized photoelectrochemical devices.Graphical Increased Solar-Driven Chemical Transformations through Surface-Induced Benzoperylene Aggregation in Dye-Sensitized Photoanodes. Benzo[ghi]perylenetriimide (BPTI) dyes are investigated to reveal the effect of aggregation by π-stacking on photovoltaic parameters in dye-sensitized devices. Photoanodes with aggregating BPTIs show both J- and H- aggregation phenomena leading to enlarged visible light absorbance and increased electron injection. The use of aggregating BPTI outperforms a non-aggregation BPTI with fivefold in terms of photocurrent and product generation.

The plasmonic effect of Cu on tuning CO2 reduction activity and selectivity.

Copper (Cu) has been widely used for catalyzing the CO2 reduction reaction (CO2RR), but the plasmonic effect of Cu has rarely been explored for tuning the activity and selectivity of the CO2RR. Herein, we conducted a quantitative analysis on the plasmon-generated photopotential (Ehv) of a Cu nanowire array (NA) photocathode and found that Ehv exclusively reduced the apparent activation energy (Ea) of reducing CO2 to CO without affecting the competitive hydrogen evolution reaction (HER). As a result, the CO production rate was enhanced by 52.6% under plasmon excitation when compared with that under dark conditions. On further incorporation with a polycrystalline Si photovoltaic device, the Cu NA photocathode exhibits good stability in terms of photocurrent and syngas production (CO : H2 = 2 : 1) within 10 h. This work validates the crucial role of the plasmonic effect of Cu on modulating the activity and selectivity of the CO2RR.

Enhanced photocatalytic activity of amphiphilic single-walled carbon nanohorn–In0.2Cd0.8S composites for water splitting

Amphiphilic SWCNH–In0.2Cd0.8S photocatalysts with various contents of amphiphilic SWCNHs have been prepared and characterized. The photocurrent density and H2 production rate of the 0.38 wt% amphiphilic SWCNH–In0.2Cd0.8S photoelectrode (0.38 mA cm−2 and 3.73 μmol h−1 cm−2, respectively) were 1.6 and 2.88 times higher, respectively, than those of the bare In0.2Cd0.8S photoelectrode. The improved photocatalytic hydrogen evolution efficiency of the 0.38 wt% amphiphilic SWCNH–In0.2Cd0.8S photoelectrode is attributed to a synergetic effect of the intrinsic properties of its components, including excellent charge transfer and separation at the interface between the amphiphilic SWCNHs and the In0.2Cd0.8S photocatalyst.

Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method

Morphological and optical properties of a multilayer film (CAZO/CZAO/ZACO) prepared by spin-coating method and deposited on a glass substrate were evaluated. The study was initially carried out for each layer, individually and then as a multilayer subsequently. Structural properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectra (IR) and X-ray photoelectron Spectroscopy (XPS) showed the presence of three phases of zinc, copper and silver oxides at different levels. The CZAO sample observed with a scanning electron microscope (SEM) showed an excellent porous surface with a large deformation in the multilayer configuration. Doping with zinc and copper in the silver crystal lattice improved the crystal structure and reduced the optical energy gap, thus increasing the optical absorbance and refractive index. The dielectric constants εr and εi showed an increase in the optical polarization values for lower photonic energies. The maximum degradation rate for photocatalysts of methylene blue was 89 % for a 5-h exposure period with CAZO/CZAO/ZACO while it reached 71 % for the CZAO sample during the same time period. The sensitivity of samples to light proved that the presence of ultraviolet radiation increases the number of holes trapped by oxygen ions and causes more free electrons and contribute to a better production of photocurrent than in darkness.

Investigating the performance of nickel molybdate nanostructure in dye sensitized solar cells: Computational and experimental analysis

This study explores both computational and experimental aspects of third-generation solar cells, specifically dye-sensitized solar cells (DSSCs) using Nickel Molybdate (NiMoO4) as both a new alternative electron transport layer (working electrode, WE) and counter electrode (CE). The synthesized NiMoO4 nanoparticles have an average size of 800 nm with crystalline size of 24.12 nm using Scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy. The results indicate that the DSSCs based on NiMoO4 exhibit low photovoltaic performance due to poor photocurrent production. However, when NiMoO4 is employed as the WE (with platinum serving as the CE); it yields a better short circuit current (Jsc = 20.04 μA/cm2) and overall photovoltaic performance compared to TiO2 WE (with NiMoO4 serving as the CE) (Jsc = 0.23 μA/cm2). Interestingly, the DSSCs with NiMoO4 as WE featured the lowest performance degradation (90 % efficiencies has been maintained after 250 h). Additionally, this study investigates the distribution of electrolyte between NiMoO4/Pt and TiO2/NiMoO4 slabs using molecular dynamics (MD) simulations, highlighting its effective contribution to ionic conductivity (Λ), ultimately leading to an increase in photocurrent for the NiMoO4/Pt system (Λ of 27.51 10−4 S.m2/mol) compared to the TiO2/NiMoO4 (Λ of 13.45 10−4 S.m2/mol). Interestingly, the iodide ions interact more tightly with the TiO2 semiconductor (at a distance of 0.32 nm) than with NiMoO4.

Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Dots Incorporation.

By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology for the inclusion of high densities of colloidal PbS QDs in a MAPbI3 (methylammonium lead iodide) perovskite matrix as a means to enhance the spectral window of photon absorption of the perovskite host film and allow photocurrent production below its bandgap. The QDs were introduced in the perovskite matrix in different sizes and concentrations to study the formation of quantum-confined levels within the host bandgap and the potential formation of a delocalized intermediate mini-band (IB). Pronounced sub-bandgap (in NIR) absorption was optically confirmed with the introduction of QDs in the perovskite. The consequent photocurrent generation was demonstrated via photoconductivity measurements, which indicated IB establishment in the films. Despite verifying the reduced crystallinity of the MAPbI3 matrix with a higher concentration and size of the embedded QDs, the nanostructured films showed pronounced enhancement (above 10-fold) in NIR absorption and consequent photocurrent generation at photon energies below the perovskite bandgap.

Small-Molecule Analysis Based on DNA Strand Displacement Using a Bacteriorhodopsin Photoelectric Transducer: Taking ATP as an Example.

A uniformly oriented purple membrane (PM) monolayer containing photoactive bacteriorhodopsin has recently been applied as a sensitive photoelectric transducer to assay color proteins and microbes quantitatively. This study extends its application to detecting small molecules, using adenosine triphosphate (ATP) as an example. A reverse detection method is used, which employs AuNPs labeling and specific DNA strand displacement. A PM monolayer-coated electrode is first covalently conjugated with an ATP-specific nucleic acid aptamer and then hybridized with another gold nanoparticle-labeled nucleic acid strand with a sequence that is partially complementary to the ATP aptamer, in order to significantly minimize the photocurrent that is generated by the PM. The resulting ATP-sensing chip restores its photocurrent production in the presence of ATP, and the photocurrent recovers more effectively as the ATP concentration increases. Direct and single-step ATP detection is achieved in 15 min, with detection limits of 5 nM and a dynamic range of 5 nM-0.1 mM. The sensing chip exhibits high selectivity against other ATP analogs and is satisfactorily stable in storage. The ATP-sensing chip is used to assay bacterial populations and achieves a detection limit for Bacillus subtilis and Escherichia coli of 102 and 103 CFU/mL, respectively. The demonstration shows that a variety of small molecules can be simultaneously quantified using PM-based biosensors.

Nickel phosphate improved silicon nanowires arrays hybrid nanostructures for solar-driven photoelectrochemical hydrogen production

Solar-driven photoelectrochemical (PEC) hydrogen production is a promising and environmentally friendly approach to relieve energy crisis and serve the carbon neutrality goal. Silicon nanowires (SiNWs), as one of p-type semiconductors, have more negative conduction band position than the water-resolved hydrogen potential, and wide range of light absorption due to their narrow band gap. Their PEC performance can be further improved by co-catalysts, and they can be used as photocathodes for hydrogen production. In this work, nickel phosphate (Ni3(PO4)2) was in situ decorated onto the SiNWs via a chemical vapor deposition (CVD). The Ni3(PO4)2 nanoparticles with diameters of about 20 to 50 nm were uniformly distributed on SiNWs arrays to construct heterostructures (Ni3(PO4)2-SiNWs). The Ni3(PO4)2-SiNWs composite showed a low onset potential to trigger water reduction. Compared with SiNWs, the Ni3(PO4)2-SiNWs composite had a much higher photocurrent and better PEC hydrogen production performance, which exhibited a stable photocurrent density of 16 mA cm−2 at 0 V (vs. reversible hydrogen electrode (RHE)) under simulated amplitude modulation (AM) 1.5G solar irradiation. This work provided a new solution to obtain nickel phosphate and fabricate the SiNWs-based photocathode.

(M,N) codoping (M = Nb or Ta) and CoO nanoparticle decoration of TiO2 nanotubes: synergistic enhancement of visible photoelectrochemical water splitting

The (M,N) codoping of TiO2 and the formation of heterojunctions by association with co-catalyst nanoparticles are two approaches that can improve the efficiency of TiO2 used as photoanodes for PEC water splitting. In this study, reactive pulsed laser deposition (PLD) of CoO nanoparticles on the surface of (M,N)-codoped TiO2 nanotubes has been used to combine these two methods. The (M,N) codoping reduced the band gap of TiO2 nanotubes and the subsequent nanodecoration significantly increased the photocurrent production under simulated sunlight and visible light conditions. The most significant improvement was obtained for (Nb,N) TiO2-NTs decorated with CoO-NPs, which showed a factor of 3 increase, and a significant contribution from the visible part of the spectrum, which accounts for 40% of the photocurrent generated in this sample. Our results suggest that this enhancement is due to a synergistic effect between the (M,N) codoping of TiO2-NTs and the presence of CoO-NPs through the formation of a high density of local triple phase interface (TPI) (n-TiO2/p-CoO/electrolyte). A modification of the band energy structure at these TPIs allows better extraction of charge carriers generated by visible light in (M,N) TiO2-NTs thanks to the presence of CoO nanoparticles.

One-step synthesis of multiple electron migration channels TiO2/Fe2O3@Ti3C2 MXene heterojunction composite for high efficiency photo-catalytic hydrogen production

Photo-catalytic hydrogen (H2) production provides a promising technology to tackle the non-renewable energy shortage and environmental pollution problem. However, the rapid recombination of the electron-hole pairs and poorer electric conduction characteristic restrict photo-catalytic H2 production. In this work, a multiple electron migration channels TiO2/Fe2O3@Ti3C2 composite hetero-structure was synthesized by one-step hydrothermal with Ti3C2 in situ autoxidation for Photo-catalytic H2 production. The morphology structures, crystallization properties electrochemical properties were characterized Systematically. Photo-catalytic experiments reveal that the TiO2/Fe2O3@Ti3C2 photo-catalyst displays enhanced response to visible light, increased transient photo-current and excellent photo-catalytic H2 production activity. The hydrogen production rate reached 1634.64 μmol/g/h, which was 9.7 and 16 times that of Ti3C2/TiO2 and single Fe2O3, respectively. The remarkably photo-catalytic H2 production performance of TCTF photo-catalyst was attributed to multiple electron-transfer channels, abundant interface contact sites and excellent light absorption. This research indicates that the hetero-structure photo-catalyst will provide significance insights into the rational design of low-cost, environmentally friendly and high-performance photo-catalysts for photo-catalytic H2 production and other solar-to-fuels conversion and applications.

Photoelectrochemical Selective Oxidation of Glycerol to Glyceraldehyde with Bi-Based Metal-Organic-Framework-Decorated WO3 Photoanode.

The conversion of glycerol to high-value-added products via photoelectrochemical (PEC) oxidation has emerged as a promising approach for utilizing a sustainable and clean energy source with environmental and economic benefits. Moreover, the energy requirement for glycerol to produce hydrogen is lower than that for pure water splitting. In this study, we propose the use of WO3 nanostructures decorated with Bi-based metal-organic frameworks (Bi-MOFs) as the photoanode for glycerol oxidation with simultaneous hydrogen production. The WO3-based electrodes selectively converted glycerol to glyceraldehyde, a high-value-added product, with remarkable selectivity. The Bi-MOF-decorated WO3 nanorods enhanced the surface charge transfer and adsorption properties, thereby improving the photocurrent density and production rate (1.53 mA/cm2 and 257 mmol/m2·h at 0.8 VRHE). The photocurrent was maintained for 10 h, ensuring stable glycerol conversion. Furthermore, at 1.2 VRHE, the average production rate of glyceraldehyde reached 420 mmol/m2·h, with a selectivity of 93.6% between beneficial oxidized products over the photoelectrode. This study provides a practical approach for the conversion of glycerol to glyceraldehyde via the selective oxidation of WO3 nanostructures and demonstrates the potential of Bi-MOFs as a promising cocatalyst for PEC biomass valorization.

Vacancy engineered BiVO4 photoanode realizes efficient photoelectrochemical CH3OH oxidation in near-neutral media: Active site regulation improves HCHO selectivity

Photoelectrochemical (PEC) CH3OH oxidation holds great promise for sustainably obtaining high value-added HCHO. Low HCHO yield and selectivity are two major constraints to the development of PEC CH3OH oxidation. Herein, we deliver the first report of efficient PEC CH3OH oxidation catalyzed by vacant BiVO4 (BVO) photoanode derived from electrolyte photooxidation and disclose the oxygen vacancy (OV)-induced catalytic sites shift for HCHO selectivity modulation. The near-neutral electrolyte solution provides an excellent environment for alcohol-aldehyde conversion and stable performance of BVO photoanode. OVs promote photogenerated carrier separation, thus ensuring a high photocurrent density and efficient HCHO production for the BVO photoanode. More importantly, the introduction of OV changes the adsorption site for CH3OH molecules from the Bi site to V site of BVO, which enhances the adsorption of CH3OH molecules, and reduces the key C-H activation energy barrier and the energy required for HCHO desorption, collectively boosting the evolution rate and selectivity of HCHO. Thus, OV engineered BVO photoanode exhibits tunable Faraday efficiencies for CH3OH oxidation of 88.4%, 94.7% and 85.6% at 0.8 VRHE, 1.0 VRHE and 1.2 VRHE, respectively, and achieves a prominent HCHO production rate of 579.9 mmol m-2h−1 and a stable photocurrent density of 3.4 mA cm−2 at 1.2 VRHE in near-neutral electrolyte. This work may inspire the future work for PEC chemicals high value-added conversion by using vacancy engineering and matching suitable electrolyte solution.

Near-infrared light-induced photoelectrochemical biosensor based on plasmon-enhanced upconversion nanocomposites for microRNA-155 detection with cascade amplifications

Herein, a novel near-infrared (NIR) light-driven photoelectrochemical (PEC) biosensor based on NaYF4:Yb3+, Er3+@Bi2MoO6@Bi (NYF@BMO@Bi) nanocomposites was elaborately developed to achieve highly sensitive detection of microRNA-155 (miRNA-155). To realize signal enhancement, the coupled plasmonic bismuth (Bi) nanoparticles were constructed as an energy relay to facilitate the transfer of energy from NaYF4:Yb3+, Er3+ to Bi2MoO6, ultimately enabling the efficient separation of electron-hole pairs of Bi2MoO6 under the irradiation of a 980 nm laser. For constructing biosensing system, the initial signal was firstly amplified after the addition of alkaline phosphatase (ALP) in conjunction with the biofunctionalized NYF@BMO@Bi nanocomposites, which could catalyze the conversion of ascorbic acid 2-phosphate into ascorbic acid, and then consumed the photoacoustic holes created on the surface of Bi2MoO6 for the enlarging photocurrent production. Upon addition of target miRNA-155, the cascade signal amplification process was triggered while the ALP-modified DNA sequence was replaced and then followed by the initiation of a simulated biocatalytic precipitation reaction to attenuate the photocurrent response. On account of the NIR-light-driven and cascade amplifications strategy, the as-constructed biosensor was successfully utilized for the accurate determination of miRNA-155 ranging from 1 fM to 0.1 μM with a detection limit of 0.32 fM. We believed that the proposed nanocomposites-based NIR-triggered PEC biosensor could provide a promising platform for effective monitoring other tumor biomarkers in clinical diagnostics.

Photocurrent Production from Cherries in a Bio-Electrochemical Cell

In recent years, clean energy technologies that meet ever-increasing energy demands without the risk of environmental contamination has been a major interest. One approach is the utilization of plant leaves, which release redox-active NADPH as a result of photosynthesis, to generate photocurrent. In this work, we show for the first time that photocurrent can be harvested directly from the fruit of a cherry tree when associated with a bio-electrochemical cell. Furthermore, we apply electrochemical and spectroscopic methods to show that NADH in the fruit plays a major role in electric current production.

Thermoelectric voltage triggered self-biased photoelectrochemical water splitting utilizing visible light active Ag/NaNbO3 nanocomposite photoanode

Nanostructure semiconductor photoactive materials are often used as working photoelectrodes to absorb solar light in conventional photoelectrochemical (PEC) cells for water splitting to demonstrate enhanced PEC performance. However, an external bias is required to start PEC water splitting reactions for the generation of hydrogen. Here, we demonstrate a novel way of designing a self-biased hybrid system that combines a darkened thermoelectric device (TE) and a photoelectrochemical cell with a visible light-active n-type Ag/NaNbO3 photoanode to produce hydrogen via water splitting by utilizing the entire solar spectrum. This method can combine utilization of a visible light photon energy from the Ag/NaNbO3 photoanode with thermal energy from the darkened TE device to overcome the overpotential requirements. Upon light illumination, the photoactive behaviour of the Ag/NaNbO3 photoanode and the voltage generated from the darkened TE device in our hybrid system modifies the band positions of an Ag/NaNbO3 photoanode and spontaneously provide the external overpotential requirement for the PEC process and enhances the H2 production. Compared to the stand-alone PEC device, the TE-coupled PEC hybrid system exhibited ∼17 times enhancement in the photocurrent density and H2 production at zero bias. The electrochemical impedance spectroscopy analysis also shows that the charge transfer process gets significantly enhanced in the hybrid PEC system compared to the PEC cell alone. This finding indicates the synergistic coupling between TE and PEC cells, where a single light energy source can increase H2 production in the hybrid systems without needing an external bias.