Photoelectrochemical UV Detector Based on High-Temperature Resistant ITO Nanowire Network Transparent Conductive Electrodes: Both the Response Range and Responsivity Are Improved

UV transparent conductive electrodes based on transferable ITO nanowire networks were prepared to solve the problem of low UV light utilization in conventional photoelectrochemical UV detectors. The mutually cross-linked ITO nanowire network achieved good electrical conductivity and light transmission, and the novel electrode had a transmission rate of more than 80% throughout the near-UV and visible regions. Compared to Ag nanowire electrodes with similar functionality, the chemical stability of the ITO nanowire transparent conductive electrode ensured that the device worked stably in iodine-based electrolytes. More importantly, ITO electrodes composed of oxides could withstand temperatures above 800 °C, which is extremely critical for photoelectrochemical devices. After the deposition of a TiO₂ active layer using the high-temperature method, the response range of the photoelectrochemical UV detector was extended from a peak-like response between 300-400 nm to a plateau-like response between 200-400 nm. The responsivity was significantly increased to 56.1 mA/W. The relationship between ITO nanowire properties and device performance, as well as the reasons for device performance enhancement, were intensively investigated.

Preparation of ZnWO4/TiO2 composite film and its photocathodic protection for 304 stainless steel under visible light

ZnWO₄/TiO₂ composite films were fabricated on TiO₂ substrate by hydrothermal method. The ZnWO₄ nanorods-sensitized TiO₂ coupled with 304 stainless steel was served as photoelectrode to study its anticorrosion effect for metal. Under visible light, the photocathodic protection ability of TiO₂ and ZnWO₄/TiO₂ composite film was measured by photoelectrochemical program on potentiostat. Open circuit potential variation result showed that sanmartinite ZnWO₄ nanorods could enhance the photoelectrochemical activity of TiO₂, and the ZnWO₄/TiO₂ composite films could absorb energy and store electrons to play a role in corrosion protection for metal.

Construction of Z-Scheme g-C₃N₄/CNT/Bi₂Fe₄O₉ Composites with Improved Simulated-Sunlight Photocatalytic Activity for the Dye Degradation

In this work, ternary all-solid-state Z-scheme g-C₃N₄/carbon nanotubes/Bi₂Fe₄O₉ (g-C₃N₄/CNT/BFO) composites with enhanced photocatalytic activity were prepared by a hydrothermal method. The morphology observation shows that ternary heterojunctions are formed in the g-C₃N₄/CNT/BFO composites. The photocatalytic activity of the samples for the degradation of acid orange 7 was investigated under simulated sunlight irradiation. It was found that the ternary composites exhibit remarkable enhanced photocatalytic activity when compared with bare BFO and g-C₃N₄/BFO composites. The effect of the CNT content on the photocatalytic performance of the ternary composites was investigated. The photocatalytic mechanism of g-C₃N₄/CNT/BFO was proposed according to the photoelectrochemical measurement, photoluminescence, active species trapping experiment and energy-band potential analysis. The results reveal that the introduction of CNT as an excellent solid electron mediator into the ternary composites can effectively accelerate the electron migration between BFO and g-C₃N₄. This charge transfer process results in highly-efficient separation of photogenerated charges, thus leading to greatly enhanced photocatalytic activity of g-C₃N₄/CNT/BFO composites. Furthermore, the g-C₃N₄/CNT/BFO composites also exhibit highly-efficient photo-Fenton-like catalysis property.

Phase transformation synthesis of TiO2/CdS heterojunction film with high visible-light photoelectrochemical activity

CdS/TiO₂ heterojunction film used as a photoanode has attracted much attention in the past few years due to its good visible light photocatalytic activity. However, CdS/TiO₂ films prepared by conventional methods (successive ionic layer adsorption and reaction, chemical bath deposition and electrodeposition) show numerous grain boundaries in the CdS layer and an imperfect contact at the heterojunction interface. In this study, we designed a phase transformation method to fabricate CdS/TiO₂ nanorod heterojunction films. The characterization results showed that the CdS layer with fewer grain boundaries was conformally coated on the TiO₂ nanorod surface and the formation mechanism has been explained in this manuscript. Moreover, the prepared CdS/TiO₂ films show a high photocatalytic activity and the photocurrent density is as high as 9.65 mA cm^-2 at 0.80 V versus RHE. It may be attributed to fewer grain boundaries and a compact heterojunction contact, which can effectively improve charge separation and transportation.

Enhanced Photocatalytic Activity of NaBH₄ Reduced BiFeO₃ Nanoparticles for Rhodamine B Decolorization

In this work, oxygen vacancies were introduced onto the surface of BiFeO₃ nanoparticles by NaBH₄ reduction method to yield oxygen-deficient BiFeO_3−x samples. Comprehensive analysis on the basis of high-resolution transmission electron microscopy (HRTEM) observation and X-ray photoelectron spectrum (XPS) confirms the existence of surface oxygen vacancies on the BiFeO_3−x nanoparticles. The photocatalytic activity of as-prepared BiFeO_3−x samples was evaluated by the decolorization of rhodamine B (RhB) under simulated sunlight irradiation. The experimental results indicate that the photocatalytic activity of samples is highly related to the NaBH₄ reduction time, and the BiFeO_3−x sample reduced for 40 min exhibits the highest photocatalytic efficiency, which is much higher than that of pristine BiFeO₃ nanoparticles. This can be explained by the fact that the surface oxygen vacancies act as photoinduced charges acceptors and adsorption sites suppress the recombination of photogenerated charges, leading to an increasing availability of photogenerated electrons and holes for photocatalytic reaction. In addition, the obtained BiFeO_3−x sample exhibits good photocatalytic reusability.

Growth and photocatalytic performance of carambola-like TiO2 consisting of nanosheets exposed {001} facets

Carambola-like TiO₂ was synthesized via a one-step solvothermal method for the first time, in which enhanced photocatalytic performance was observed.

TiO2/Bi2S3 core–shell nanowire arrays for photoelectrochemical hydrogen generation

This paper demonstrates the procedure for construction of nontoxic TiO₂/Bi₂S₃ core–shell NWA photoanodes for PEC hydrogen generation.

The enhanced photoactivity of hydrogenated TiO2@reduced graphene oxide with p–n junctions

The preparation processes of hydrogenated TiO₂@reduced graphene oxide composites with p–n heterojunctions.