Efficient solar-powered water oxidation over BiVO4-based anodes requires coupling photoactive semiconductors to improve inferior activity and stability. Herein, we examine how functionalization with coated tungsten trioxide WO3 affects the photoelectrocatalytic performance of TaON–BiVO4 photoanodes prepared by the doctor-blade method. The effects of the formation of the particularly-porous microstructure and PEC performance of the resulting anodes are explored. Significant enhancements were achieved in water oxidation photocurrent densities at 1.23 V (vs. RHE) with the use of TaON–BiVO4/WO3 photoanodes compared to unmodified TaON–BiVO4. All the composites and photoanodes were studied via numerous characterization methods. Besides, the formation process and probable transfer mechanism of photoinduced carriers were also investigated in detail.
Han Yujun,Shi Yinteng,Wang Dandan,Zhou Hantao,Chen Jixiang
Ni/ZrO 2 (Ni/Zr) and Ni/WO 3 -ZrO 2 (Ni/ x WZr, x denotes WO 3 /ZrO 2 mass ratios) were prepared by the impregnation-direct reduction method and tested for the aqueous phase hydrogenation of phenol to cyclohexanone in an autoclave reactor. It has been found that the Ni-W alloy forms in Ni/ x WZr, and a charge transfer occurs from Ni to W. The presence of W species promotes the Ni dispersion and increases the amounts of acid sites and spilt-over hydrogen species. This leads to higher hydrogenation and direct deoxygenation activity of Ni/ x WZr than that of Ni/Zr. In addition, the W 6+ and W 4+ species, acted as Lewis acidic sites, may stabilize cyclohexanone and the hydrogenation of cyclohexanone to cyclohexanol is inhibited. Under suitable condition, the phenol conversion and the cyclohexanone selectivity reach 93.1 and 90.6% on Ni/0.8WZr, respectively.
To address the escalating concerns related to organic pollutions in aquatic environments, there is an urgent demand for exploring an efficient and eco-friendly method for the removal of organic pollutants. In this work, porous Cl-C 3 N 4 (ClCN)and step-scheme (S-Scheme) Cl-C 3 N 4 /WO 3 (ClCN/WO 3 ) composites have been designed and fabricated through a facile calcination approach for tetracycline removal under visible-light irradiation. The synthesized S-Scheme ClCN/WO 3 composites exhibited porous structures, though their visible-light absorption was lower compared to the ClCN and C 3 N 4 samples. The surface areas of the ClCN/WO 3 composites can reach 81.43 m 2 g −1 , significantly higher than that of the ClCN and C 3 N 4 samples. These composites also demonstrated prolonged carrier lifetime and improved charge separation efficiency, primarily due to the formation of S-Scheme heterostructures. Among the prepared samples, the ClCN/WO 3 -2 composite demonstrated the highest photocatalytic activity with a rate constant reaching 0.0547 min −1 , approximately 4.56 times that of pristine C 3 N 4 . Additionally, when applied to tetracycline degradation in simulated seawater, the ClCN/WO 3 -2 composite achieved a rate constant of 0.047 min −1 , outperforming the C 3 N 4 and ClCN samples. Mechanistic studies showed that the S-Scheme heterostructures markedly promoted charge separation and tetracycline degradation. Furthermore, the ClCN/WO 3 composites contributed to a reduced the biological toxicity of the degraded intermediates. This study underscores the immense potential of ClCN/WO 3 composites as high-performance photocatalysts for the photodegradation of organic pollutants under visible-light irradiation.