The Effect of Platinum Deposition on the Water Photo-Reduction at p-Cu2O Semiconductor Electrodes with Visible Light Irradiation

The surface of a p-Cu2O semiconductor photoelectrode was modifi ed by electrodeposition of Pt nanoparticles and analyzed by XRD, SEM, XPS, and EIS (electrochemical impedance spectrometry) methods besides photocurrent measurements. The XRD, SEM, and XPS analyses showed the fabrication of Cu2O fi lm and the deposition of Pt particles. On the electrodeposition of Pt nanoparticles, cathodic photocurrent was enhanced. The EIS analysis suggested that Pt nanoparticles enhance the charge transfer process to the solution

Enhanced Photoelectrocatalytic Activity of FTO/WO3/BiVO4 Electrode by Modified With Gold Nanoparticles for Water Oxidation Under Visible Light Irradiation

Gold nanoparticles were successfully deposited on FTO/WO3/BiVO4 electrode surface by means of electrolysis of AuCl4 - ions. The composite films were characterized by SEM, XPS and XRD techniques. An increase in photocurrent and a negative shift of onset potential for water oxidation were observed upon modification of the electrode surface with the Au particles. The electrochemical impedance spectroscopy was used to confirm the acceleration of charge transfer process by Au deposition at the electrode surface. The photocurrent action spectrum did not correlate with the plasmonic absorbance of Au nanoparticles at 560 nm, suggesting that the Au nanoparticles increased charge separation without undergoing a plasmon resonance effect under visible light irradiation

Developments of the efficient water-splitting electrodes under the visible light irradiation

Our recent works on the photoelectrochemistry and fabrication of the water-splitting photocatalyst for solar energy conversion were reported. The S-dope midgap states were determined by monitoring the effect of the photocurrent on the addition of several reductants. The midgap states for the S-doped anatase TiO2 has higher redox potentials than those of the Br ・/Br− and possesses the additional multiple oxidation states of S cations. The laser ablation of the BiVO4 and BiZn2VO6 photocatalytic particulates in water reduced these sizes and it was found that the thin film electrode prepared by calcining the laser-ablated BiVO4 and BiZn2VO6 suspensions showed higher photocurrent efficiencies compared with the electrodes prepared without laser-ablation. The composite electrode FTO/SnO2/BiVO4 and FTO/WO3/BiVO4 were prepared by a solution method and the photocurrent efficiencies for these electrodes were found to be increased due to the mediator effect of SnO2 and WO3, which helps the electrons in the conduction band of BiVO4 to transfer to the FTO. The new photocatalytic particulates that are active for oxygen evolution under the visible light irradiation was searched and the BiCu2PO6 was found to be active with the addition of sacrifice under the visible light irradiations

Photoelectrocatalytic performance of WO3/BiVO4 toward the dye degradation

The photocatalytic (PC) and photoelectrocatalytic (PEC) properties of WO3/BiVO4 photo-anode for organic dye degradation under visible light irradiation were studied. The performance of the electrodes was investigated by monitoring the % degradation of methylene blue (MB) as a dye sample with UV-Vis spectroscopy. To study the charge transfer rate improvement, a Cu2O electrode was employed as a photo-cathode. In addition, Ag nanoparticles were deposited on both WO3/BiVO4 and Cu2O electrodes to study the effect on the catalytic activity for MB degradation. SEM, XRD and XPS techniques were used to confirm the morphologies and composition of the modified electrodes. The effects of pH and the irradiation wavelengths were investigated to understand the condition of MB degradation process. The highest performance for MB degradation was attained when WO3/BiVO4 was used as a photo-anode and Cu2O/Ag as a photo-cathode under the PEC process

Efficient Photocatalytic Activity of Water Oxidation over WO3/BiVO4 Composite under Visible Light Irradiation

A coupled WO3/BiVO4 thin film has been deposited on FTO substrate by a spin coating method from precursor solutions. The composite films were characterized by AFM, SEM, XPS and XRD techniques. The incident photon to current efficiency (IPCE) of BiVO4 electrode was increased by ten times when a WO3 film was layered between the BiVO4 layer and the FTO substrate. The enhanced performance of WO3/BiVO4 composite film electrode is mainly ascribed to the effective electron-hole separations at the semiconductor heterojunction. A schematic mechanism of charge transfer was proposed to explain the photocurrent enhancement for the WO3/BiVO4 electrode surface