High Photoelectrochemical Activity Research Articles

High photoelectrochemical activity of CuO nanoflakes grown on Cu foil

CuO is a narrow band gap p-type semiconducting material having a wide range of applications. However, it is quite challenging to obtain phase pure CuO nanostructures grown directly on Cu substrate as most of the synthesis techniques like thermal oxidation results in the formation of additional Cu2O phase. In this work, we report the growth of CuO nanoflakes without the formation of Cu2O by a facile two-step synthesis process which consist of electrochemical anodization of Cu foil followed by low-temperature hydrothermal treatment at 100 °C. The phase purity of the sample is confirmed through XRD, XPS, and HRTEM. Further, photocurrent response of the sample is evaluated, and a rapid thermal treatment was used to improve the photo-response without altering the phase and morphology of the CuO nanoflakes. Such a process at 400 °C for 10 s resulted in a high photocurrent density of −4.6 mAcm−2 (at 0.05 V vs. RHE under AM 1.5G conditions). Electrochemical impedance spectroscopy and Mott Schottky analysis shows the direct role of rapid thermal treatment in increasing the charge carrier density of the sample.

In-situ Reduction Synthesis of Bi/BiOI Heterostructure Films with High Photoelectrochemical Activity

The Bi/BiOI heterostructure films grew perpendicular to the FTO substrates were synthesized in-situ through an electrochemical deposition and hydrogen reduction method. The metallic Bi nanoparticles were decorated onto the surface of BiOI nanosheets via an in-situ reduction, induced 6.3 times improvement of photocurrent density, compared to the pristine BiOI at 1.23 V vs. reversible hydrogen electrode(RHE). The enhancement of photoelectrochemical performance was attributed not only to the efficient separation of charge resulted from surface plasmon resonance effect, but also to the fast charge transfer at the interface due to the in-situ reduction of the films. This work provided a simple and facile strategy to in-situ construct heterostructure films, and showed an effective method to improve the photoelectrochemical activity of Bi-based semiconductors.

P-n-Sensitized Heterostructure Co3O4/Fullerene with Highly Efficient Photoelectrochemical Performance for Ultrasensitive DNA Detection.

Significantly sensitized architectures meeting the requirements of high photoelectric conversion efficiency and promising photocurrent intensity are extremely desirable, but challenges in sensitizer development and efficiency in photoelectrochemical (PEC) fields remain. In this paper, the p-type metal oxide semiconductor Co3O4 was attached as an effective photosensitizer to n-type fullerene C60 in view of appropriately matched energy band levels to form the highlighted p-n-sensitized heterostructure Co3O4/fullerene, with facilitated charge separation and accelerated carrier mobility. Compared with traditional p-n heterostructure, the p-n-sensitized heterostructure Co3O4/fullerene illustrated a wider range for light absorption with further enhanced light-harvesting capability, thereby leading to more exceptional PEC performance containing remarkably promoted photoelectric conversion efficiency and improved photocurrent intensity. Impressively, the photocurrent intensity obtained by Co3O4/fullerene was about sixfold higher than that of fullerene alone, and this achievement was quite favored compared to the reported works for fullerene sensitization, which could be responsible for the advancement of detection sensitivity for the subsequently constructed biosensor. Unambiguously, given the p-n-sensitized heterostructure Co3O4/fullerene of high PEC activity, the well-fabricated three-dimensional DNA walker applied as a target-cascade signal amplification strategy, and the Au layer employed as the specific linker between the photoactive material and the signal amplification product, a smart PEC biosensor was successfully enabled for ultrasensitive investigation of the model DNA (a fragment of the p53 gene), showing a wide linear range of 60 to 1 × 105 aM and a detection limit of 20 aM. This proposed PEC biosensor provided acceptable insights into the clinic analysis, disease therapies, and other relevant subjects.

Electrochemistry of Sputtered Hematite Photoanodes: A Comparison of Metallic DC versus Reactive RF Sputtering.

The water splitting activity of hematite is sensitive to the film processing parameters due to limiting factors such as a short hole diffusion length, slow oxygen evolution kinetics, and poor light absorptivity. In this work, we use direct current (DC) magnetron sputtering as a fast and cost-effective route to deposit metallic iron thin films, which are annealed in air to obtain well-adhering hematite thin films on F:SnO2-coated glass substrates. These films are compared to annealed hematite films, which are deposited by reactive radio frequency (RF) magnetron sputtering, which is usually used for depositing metal oxide thin films, but displays an order of magnitude lower deposition rate. We find that DC sputtered films have much higher photoelectrochemical activity than reactive RF sputtered films. We show that this is related to differences in the morphology and surface composition of the films as a result of the different processing parameters. This in turn results in faster oxygen evolution kinetics and lower surface and bulk recombination effects. Thus, fabricating hematite thin films by fast and cost-efficient metallic iron deposition using DC magnetron sputtering is shown to be a valid and industrially relevant route for hematite photoanode fabrication.

Ni-Doped BiVO4 with V4+ Species and Oxygen Vacancies for Efficient Photoelectrochemical Water Splitting

Bismuth vanadate is a promising photoanode material for photoelectrochemical (PEC) water splitting, but its activity and stability need to be further improved. In this work, we synthesized Ni-doped BiVO4 abundant with V4+ species and oxygen defects through an in situ electrodeposition method. The effective doping can decrease the particle size of BiVO4 and lead to the formation of V4+ species/oxygen defects. Accordingly, the doped and defective BiVO4 showed high optical absorption and rapid charge transfer, and further showed much higher PEC activity than pure BiVO4. Specifically, 5-Ni-BiVO4 exhibits the highest activity in PEC water splitting, with a photocurrent of 2.39 mA/cm2 at 1.23 V versus RHE (the reversible hydrogen electrode), which is 2.5 times higher than pure BiVO4 (0.94 mA/cm2), and much higher incident photon-to-current efficiency (IPCE) value of 45% (while only 25% for BiVO4 at ca. 400 nm). This work provides an in situ method for the development of a high-performance photoanode.

Photoelectrochemical sensor based on composite of CdTe and nickel tetra-amined phthalocyanine covalently linked with graphene oxide for ultrasensitive detection of curcumin

A novel efficient photoelectrochemical (PEC) sensor was assembled for curcumin (Cur) detection using 2-mercaptoacetic acid (TGA)-capped CdTe nanoparticles and nickel tetra-amined phthalocyanine-linked graphene oxide (TGA-CdTe@NiTAPc-Gr). The TGA-CdTe nanoparticles could be firmly immobilized on the thin film structure of NiTAPc-Gr in a hydrogen-bonded manner, thus producing the proposed PEC sensor with a high photoelectrochemical activity of TGA-CdTe nanoparticles and excellent stability of NiTAPc-Gr. The TGA-CdTe@NiTAPc-Gr thin film showed a stronger blue light absorption property than the individual precursors, and this resulted in the sensitive detection of Cur ranging from 0.25–100 μM with a detection limit of 12.50 nM. In addition, the PEC sensor exhibited a high sensitivity and selectivity and quite good reproducibility. Thus, it shows potential for Cur detection in real samples.

ZnO-TiO2 core-shell nanowires decorated with Au nanoparticles for plasmon-enhanced photoelectrochemical water splitting

The present work reports the development of Au-nanoparticle decorated ZnO-TiO2 core-shell nanowires on the Si-wafer. The developed Au-nanoparticle decorated ZnO-TiO2 core-shell nanowires exhibit a unique structure with uniform sensitization of Au-nanoparticles with the diameter in the range of 5–9 nm on the ZnO-TiO2 core-shell heterostructure. This unique structure of Au-nanoparticle decorated ZnO-TiO2 core-shell nanowires demonstrates an enhanced photocurrent density of 1.63 mAcm−2 upon illumination by visible light unveiling high photoelectrochemical water splitting activity. This photocurrent density is higher than the pristine ZnO nanowires (0.51 mAcm−2) and ZnO-TiO2 core-shell nanowires (1.23 mAcm−2). Furthermore, photoelectrochemical water splitting efficiency of Au-nanoparticle decorated ZnO-TiO2 core-shell nanowires was found to be 0.70%, which is higher than the ZnO nanowires (0.22%) and ZnO-TiO2 core-shell nanowires (0.53%) at the same applied potential of +0.8 VRHE. The improved photocurrent density and efficiency is due to the enhanced absorbance in the visible region owing to the surface plasmon resonance effect of Au-nanoparticle, effective withdrawal of hot electron from the Au-nanoparticle at the interface of metal/semiconductor due to Schottky barrier as well as excellent charge-separation and transportation originating from the core-shell nanowires.

ZnO/CdS/PbS nanotube arrays with multi-heterojunctions for efficient visible-light-driven photoelectrochemical hydrogen evolution

High performance, low cost and sustainable photocatalytic evolution of hydrogen is a promising energy supply alternative for modern society to resolve the depletion crisis of fossil fuel. The design of multi-heterojunction visible-light photocatalysts combined with electrochemical means is considered one of the most attractive options in recent years. In this work, a photoanode composed of top-opened ZnO/CdS/PbS nanotube arrays (ZnO/CdS/PbS ONTs) with multi-heterojunctions was synthesized via a three-step process, i.e. hydrothermal treatment, chemical bath deposition and successive ionic layer adsorption reaction (SILAR). This as-prepared photoanode exhibited remarkable photoelectrochemical activity under visible light irradiation. The photocurrent density and photoelectrochemical hydrogen evolution efficiency of the optimized ZnO/CdS/PbS ONTs reached up to 14.2 mA cm−2 and 5.5 mL cm−2 h−1 at 0.0 V vs. Ag/AgCl, respectively. The efficiency was 3.1 times that of top-closed ZnO/CdS nanotubes (1.8 mL cm−2 h−1). The experimental results suggest that the high photoelectrochemical activity can be ascribed to the inherent advantages of the structural and successive energy level relays design: on the one hand, the top-opened nanotube structure significantly enlarges surface area of the nanostructure, which facilitates efficient light absorption and rapid mass transport; on the other hand, the well-matched band energy edge of the multi-heterojunction interfaces literally build efficient electron highways to deliver electrons to reaction sites and reduce the recombination of photogenerated charge carriers.

Co3O4 Nanoparticles Modified TiO2 Nanotube Arrays with Improved Photoelectrochemical Performance

Co3O4 modified TiO2 nanotube arrays (TiO2-NTs) were successfully fabricated by electrodeposition and thermal oxidation process. The prepared samples were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopic (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectroscopy. The photoelectrocatalytic properties of as-prepared samples were investigated under visible light and UV-vis light irradiation. Meanwhile, taking methyl orange aqueous solution as target substrate for photoelectrocatalytic degradation experiments, the degradation rate under UV-vis light irradiation and dark condition were evaluated. The prepared Co3O4/TiO2-NTs exhibited much higher photoelectrochemical activity than TiO2-NTs under visible light irradiation and UV-vis light irradiation. The degradation rate of methyl orange on Co3O4/TiO2-NTs electrode reaches 90.7% under applied potential of 1.3 V and UV-vis light irradiation for 10 h, which is only 53.4% on TiO2-NTs electrode. The improved performance could be attributed to the higher photo-generated carrier concentration and carrier mobility.

Designed of bifunctional Z-scheme CuSnO3@Cu2O heterojunctions film for photoelectrochemical catalytic reduction and ultrasensitive sensing nitrobenzene

A direct Z-scheme CuSnO3@Cu2O heterojunctions photo-electroactive material were reasonably designed and fabricated by electrodeposited Cu2O on fluoride doped tin oxide (FTO) substrate followed anchoring 3D CuSnO3 microspheres onto Cu2O film. The novel 3D architectures can favor the mass transfer, provide multiple active sites and improve light absorption during the photoelectrocatalytic reactions. The artificial heterogeneous Z-scheme photoelectrochemical (PEC) system further prolong electrons path, promote the separation of photogenerated charge carriers and maintain high redox ability. As expected, the constructed Z-scheme CuSnO3@Cu2O as the photocathode show excellent dual functional properties which can not only detect the trace nitrobenzene (NB) but also undergo catalytic reduction of NB to less toxic species (aniline, AN) under visible light irradiation. Based on CuSnO3@Cu2O photocathode, the photocurrent was linearly proportional to the concentration of NB ranging from 0.5 nmol L−1 to 100 μmol L−1, and the detection limit (S/N = 3) was 0.43 nmol L−1. The fabricated sensor was successfully used to sensing the trace NB in real samples and it showed excellent anti-interference ability, good reproducibility and high stability. Besides, CuSnO3@Cu2O exhibited high PEC activity for NB reduction, 85.70% reduction efficiency was achieved within irradiation for 2.5 h. Thus, this study may provide insights into designing advanced photoeletrocatalysts for energy conversion and render a tunable platform in photoelectrochemistry for the monitor and clean-ups of environmental pollutants.

Syntheses, structures and photoelectrochemical properties of phosphite-stabilized titanium-oxo clusters containing 2,2′-biphenolato ligands

The solvothermal reaction of Ti(OiPr)4, phosphorous acid and 2,2′-biphenol under different conditions offer three titanium-oxo clusters, namely, [Ti8(μ3-O)2(μ2-O)2(μ2-OiPr)4(OiPr)8(O3PH)4bph2], (bph = 2,2′-biphenolato) [Ti8(μ4-O)2(μ2-O)2(μ2-OEt)8(OEt)8(O3PH)2bph2], and [Ti4(μ3-O)2(μ2-OiPr)2(OiPr)4{O2P(OiPr)2}2bph2], respectively. The phosphite ligands induce the formation of different core structures compared to the well-studied phosphonate-stabilized titanium-oxo clusters. The 2,2′-biphenolato ligands introduce the ligand-to-core charge-transfer (LCCT) transition and result in narrow band gap of these clusters. Photocurrent response measurements show that the clusters with {Ti8P4} and {Ti8P2} core structures have higher photoelectrochemical activity than that of {Ti4P2}.

One-Pot Synthesis of N-Graphene Quantum Dot-Functionalized I-BiOCl Z-Scheme Cathodic Materials for "Signal-Off" Photoelectrochemical Sensing of Chlorpyrifos.

A Z-scheme I-BiOCl/N-GQD (i.e., nitrogen-doped graphene quantum dot) heterojunction was prepared by a one-pot precipitation method at room temperature. The doped iodine decreased the band gap of BiOCl, the introduced N-GQDs enhanced light harvesting and prolonged the photogenerated electron lifetime, and the resultant Z-scheme heterojunction promoted the spatial separation of interfacial charges. Thus, the composite showed high photoelectrochemical activity and a big cathodic photocurrent signal. On the basis of the coordination of chlorpyrifos with surface Bi(III) of the composite, a cathodic photoelectrochemical sensor was constructed for the selective detection of chlorpyrifos. In this case, chlorpyrifos decreased the lifetime of photogenerated electrons, so the photocurrent became small. Furthermore, the photocurrent changed and the logarithm of chlorpyrifos concentration presented a linear relationship. The linear range was 0.3-80 ng mL-1, and the limit of detection was estimated to be 0.01 ng mL-1 (defined as S/N = 3). The present strategy can also be used for the design and fabrication of other PEC sensors suitable for different analytes.

The Z-scheme heterojunction between TiO2 nanotubes and Cu2O nanoparticles mediated by Ag nanoparticles for enhanced photocatalytic stability and activity under visible light

The photocatalytic reduction method was used to introduce Ag nanoparticles (Ag NPs) into the Cu2O-TiO2 nanotubes (Cu2O-TNT) prepared by electrodeposition. The Z-scheme heterojunction Cu2O-Ag-TNT (CAT-4–60) catalysts were prepared. The mechanism of the transition from the traditional P-N heterojunction enhanced by noble metal to the Z-scheme heterojunction was studied. In addition, the Z-scheme heterojunction CAT-4–60 showed the highest light absorption and the highest photoelectrochemical activity under visible light, and the photoluminescence intensity was significantly reduced. Compared with the traditional P-N heterojunction CAT-2–60, not only the photocatalytic activity of the dual Z-scheme CAT-4–60 catalyst was improved, and the removal rate of MB was 98.58% higher than TNT (45.81%), CT-60 (69.49%), AT-2 (75.1%) and CAT-2–60 (91.2%),but also the stability of Cu2O in CAT-4–60 was significantly enhanced. This work reveals the potential application of noble metal nanoparticles to enhance the Z-scheme heterojunction under visible light-driven photocatalysis, and provides new insights to the transition from traditional P-N heterojunctions to Z-scheme heterojunctions.

A photoelectrochemical immunoassay for tumor necrosis factor-α using a GO-PTCNH2 nanohybrid as a probe

A simple photoelectrochemical (PEC) immunoassay based on an amino-terminated perylene derivative (PTCNH2) was developed for highly sensitive and specific detection of tumor necrosis factor-alpha (TNF-α). Simple grinding and sonication afforded a π-π stacked graphene oxide (GO)/PTCNH2 assembly exhibiting fast electron transfer kinetics and excellent photoelectric performance, and this assembly was applied as a PEC probe. The GO-PTCNH2 assembly provided not only a large surface area, fast electron transfer kinetics and abundant active sites for further biomolecule conjugation but also high PEC activity. A “signal-off” PEC immunoassay for TNF-α was developed by assembling GO-PTCNH2 on the electrode, followed by conjugation of anti-TNF-α with GO-PTCNH2 and subsequent capture of the target protein TNF-α. The linear detection range was from 10 pg/mL–100 ng/mL with a limit of detection (LOD) of 3.33 pg/mL. This method was also successfully applied for detecting TNF-α in human serum with recoveries ranging from 92.5% to 96.6% and a relative standard deviation of less than 9.99%. For the first time, this work reports a simple PEC immunoassay achieved by using PTC-NH2 as a photoelectrochemically active probe for the detection of a tumor biomarker. This assay could be applicable to the detection of other biomarkers for clinical diagnosis.

Visible-light-driven photoelectrochemical determination of Cu2+ based on CdS sensitized hydrogenated TiO2 nanorod arrays

A CdS sensitized hydrogenated TiO2 nanorod arrays (CdS@HTNRs) film was developed for the selective visible-light-driven photoelectrochemical (PEC) sensing of Cu2+ ion. The sensitive determination was based on extremely high PEC activity of the as-prepared CdS@HTNRs, i.e, the photocurrent density of the as-prepared CdS@HTNRs electrode could reach up to 10.1 mA cm−2, which was 33.7 times higher than that of the pure HTNRs film. Dramatic photocurrent quenching was observed upon immersion of the CdS@HTNRs electrode into Cu2+ solution. The analytical principle is based on significant quenching of photocurrent, i.e, the formation of CuS and subsequent CuxS (x = 1, 2) produced on the electrode surface under illumination reduces the absorption of light and boosts the electron-hole recombination, respectively. Due to the large photocurrent density of the as-prepared CdS@HTNRs and the high selectivity of chemical recognition reaction between CdS and Cu2+, the photocurrent quenching of CuxS, is proposed to be sensitive and selective in detecting Cu2+ ion. The linear detection range could be 0.8 nM to 82.0 μM with the detection limit of 0.3 nM via controlling recognition reaction time to be 7 min. The sensor was also successfully applied in the detecting Cu2+ ion in real samples such as tap water, lake water and urine.

A ternary hybrid CdS/SiO2/TiO2 photoanode with enhanced photoelectrochemical activity

Abstract In this study, a novel ternary hybrid CdS/SiO2/TiO2 film was proposed as the phonoanode for the photocatalytic fuel cell. The samples were characterized by X-ray diffraction, scanning electron microscopy and UV–vis absorption. The photoelectrochemical activity of the ternary hybrid electrode was characterized by the photocurrent-time transient response, linear sweep voltammetry and electrochemical impedance spectroscopy. It was shown that CdS/SiO2/TiO2 yielded much higher photoelectrochemical activity than CdS/TiO2 and bare TiO2 did. The photoanode with CdS/SiO2/TiO2 showed the highest photocurrent density of 4.6 mA cm−2, exhibiting a 40% improvement over the conventional CdS/TiO2 photoanode. The roles of SiO2 and CdS in such a ternary configuration were elaborated. It was demonstrated that CdS could act as an excellent visible light captaturer to generate photo-induced charge carriers, and SiO2 as a passivation layer to suppress the interfacial recombination of electrons and holes. Moreover, SiO2 could allow for more CdS to be deposited at the photoanode owing to its high adsorption capacity. In addition, the effects of the SiO2 content and the SILAR cycle time on the performance of the CdS/SiO2/TiO2 photoanode were investigated. An optimal SiO2 content of 10% could yield the best performance. Increasing the SILAR cycle time could improve the photoelectrochemical activity.

One-step facile preparation of ZnO nanorods as high-performance photoanodes for photoelectrochemical cathodic protection

In this work, ZnO nanorod photoanodes were fabricated by electrodeposition on a conductive indium tin oxide glass substrate, enabling photoelectrochemical cathodic protection (CP) of both stainless and carbon steels in a chloride solution. The surface morphology, composition, crystalline structure and optical absorption property of the prepared ZnO photoanodes were characterized by scanning electron microscopy, energy dispersive X-ray spectrum, X-ray diffraction and UV–Visible diffuse reflection absorption spectrometry, respectively. Electrochemical and photoelectrochemical properties of the photoanodes were measured. Results demonstrate that the ZnO nanorod photoanodes are able to achieve sufficient cathodic polarization to 304 stainless steel and X52 carbon steel in 3.5 wt.% NaCl solution under light illumination. Compared to previously reported ZnO photoanodes, the mass activity of the prepared ZnO nanorod photoanodes in this work is improved nearly 10 times and 3–6 times when coupled with stainless steel and carbon steel, respectively. The unique surface nanostructure of the generated ZnO nanorods contributes to the high photoelectrochemical activity of the photoanodes. Particularly, the ZnO nanorod photoanode prepared at the depositing potential of −0.9 V (SCE) possesses the higher photoelectrochemical activity of 19.5 μA/mg than those fabricated at more negative potentials. Under identical illuminating conditions, the ZnO nanorod photoanode can cathodically polarize the stainless steel much more substantially than carbon steel, causing negative potential shifts of 306.6 mV and 39.1 mV, respectively.

Efficient synthesis of perovskite-type oxide photocathode by nonhydrolytic sol-gel method with an enhanced photoelectrochemical activity

The photoelectrochemical activity of PbTiO3 (PTO) for water splitting was studied by linear sweeping voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) techniques. The nanohydrolytic sol-gel method was used to synthesise a crystalline PbTiO3 perovskite nanoparticles. The physical and chemical properties of nanoparticles such as crystal structure, surface area, reducibility, band gap energy, particle morphology and size, surface composition and valence states were investigated by X-Ray diffraction (XRD), BET, temperature-programmed reduction (TPR), UV diffuse reflectance spectroscopy (UV-DRS), high resolution scanning and transmission electron microscopy (HR-SEM and HR-TEM) along with X-Ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). PTO nanoparticles showed pure crystallinity, high surface area (14 m2/g) and high oxygen mobility. PTO has band gap energy of 2.66 eV, which makes it active under visible light irradiation. Moreover, nanoparticles vary in size and create a core-shell structure in a way that small particles surround large particles. The core-shell structure along with a free defected sites on the surface results in high photoelectrochemical activity for water splitting reaction. The IV curve revealed that the PTO nanoparticles are a p-type electrode with the photocurrent efficiency of ≈19%. This suggests that the photoelectrode does not require external bias to initiate the water splitting and the reaction can be initiated simply by making a connection between the anode and the cathode. In addition, a great stability is observed for PTO electrodes during the reaction, as evidenced by no leaching to the reaction medium.

A highly efficient Cu(In,Ga)(S,Se)2 photocathode without a hetero-materials overlayer for solar-hydrogen production

Surface modification of a Cu(In,Ga)(S,Se)2 (CIGSSe) absorber layer is commonly required to obtain high performance CIGSSe photocathodes. However, surface modifications can cause disadvantages such as optical loss, low stability, the use of toxic substances and an increase in complexity. In this work, we demonstrate that a double-graded bandgap structure (top-high, middle-low and bottom-high bandgaps) can achieve high performance in bare CIGSSe photocathodes without any surface modifications via a hetero-materials overlayer that have been fabricated in a cost-effective solution process. We used two kinds of CIGSSe film produced by different precursor solutions consisting of different solvents and binder materials, and both revealed a double-graded bandgap structure composed of an S-rich top layer, Ga- and S-poor middle layer and S- and Ga-rich bottom layer. The bare CIGSSe photocathode without surface modification exhibited a high photoelectrochemical activity of ~6 mA·cm−2 at 0 V vs. RHE and ~22 mA·cm−2 at −0.27 V vs. RHE, depending on the solution properties used in the CIGSSe film preparation. The incorporation of a Pt catalyst was found to further increase their PEC activity to ~26 mA·cm−2 at −0.16 V vs. RHE.

One-step electrodeposition of high-quality amorphous molybdenum sulfide/RGO photoanode for visible-light sensitive photoelectrochemical biosensing

Exploiting high-quality photoactive material with visible light absorption, high photoelectrochemical (PEC) activity and stability is of great importance for developing high-performance PEC sensing. In this paper, amorphous molybdenum sulfide (a-MoSx)/reduced graphene oxide (RGO) hybrid film was directly grown on indium tin oxide (ITO) via a facile one-step electrodeposition, followed by a post annealing process. The uniform a-MoSx/RGO hybrid film exhibited significantly enhanced photocurrent, fast photoelectric switching behavior and robust stability under the visible light. Direct utilization of a-MoSx/RGO as an efficient photoanode for glucose determination had been demonstrated for the first time. Rapid response and robust stability for glucose determination in a wide linear range from 0.15 to 16 mM with a low detection limit were obtained. The reliability of detecting glucose in serum samples was demonstrated. This work stresses the importance of one-step electrodeposition preparation of a-MoSx/RGO hybrid film as high-quality photoanode for PEC bioanalysis.