RESUMEN
Volatile organic compounds (VOCs) are attracting much more attention due to their contributions to air pollution and human health problems. Photothermal catalytic oxidation is considered as an energy-saving method for the removal of VOCs. However, the efficiency of the photothermal catalytic system is still suffering from the low activity of the catalyst due to its poor response to visible light and low efficiency of charge separation. Here, few-layer CoAl-LDH (layered double hydroxide) was prepared as an advantageous support for loading Pt nanoparticles to obtain Pt-LDH, which were coated on CeO2 nanoparticles. Type II heterojunctions were formed on the interface of LDH and CeO2. In photocatalysis, the hot electrons will move to CeO2, which is better at the activation of O2 molecules, and holes will concentrate on the LDHs, which have plenty of hydroxyls to generate â¢OH radicals. Furthermore, the Schottky heterojunctions between LDH and Pt nanoparticles benefit the improvement of light absorption by the localized surface plasmon resonance of Pt nanoparticles. As a consequence, a high removal rate of toluene (75.7%) at a weight-hourly space velocity of 23340 mL/(g·h) under visible light irradiation (160 mW/cm2, λ > 400 nm) at room temperature was achieved over the Pt-LDH/CeO2 catalyst. The catalyst design provides a useful method to prepare high-efficiency photothermal catalysts.
RESUMEN
Hydrogen production from overall water splitting using SrTiO3(Al)-based semiconductors is one of the most promising routes to address energy and environmental concerns. Noble metals are needed to accelerate water splitting by promoting the charge transfer and providing active sites. However, noble metal-based catalysts have high prices and rare resources. Herein, we demonstrate a strategy to construct highly active CoxP/SrTiO3(Al) for overall water splitting. Hydrothermal method followed by an ultrasonic process was applied to prepare CoxP dots, which were loaded on the whole surface of SrTiO3(Al) as bifunctional cocatalysts. Interestingly, the CoxP dots on the (110) planes of SrTiO3(Al) were partially oxidized for the OER reaction. However, CoxP dots on the (100) planes of SrTiO3(Al) for HER kept it as it was. The as-prepared CoxP/SrTiO3(Al) photocatalyst shows a stable HER rate of 1.36 mmol-1 h-1 and OER rate of 0.635 mmol-1 h-1. The strong interaction between CoxP and SrTiO3(Al) not only facilitates rapid charge separation but also provides a highly active site for overall water splitting. Our study provides a valuable method for constructing noble-metal-free SrTiO3(Al)-based photocatalysts.
