Rational Design and Preparation of Pt–LDH/CeO₂ Catalyst for High-Efficiency Photothermal Catalytic Oxidation of Toluene

Abstract

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 •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.

Harnessing Solar Energy Towards Synergistic Photothermal Catalytic Oxidation of Volatile Organic Compounds

“…The formation of heterointerfaces narrows the bandgap and prolongs the lifetime of photoinduced charge carriers, resulting in enhanced charge mobility, and light response. [32,[117][118][119][120] The efficiency of facet-heterojunction nanocomposites CdS-Au-{010}BiVO 4 {110}-MnO x was evaluated for the decomposition of toluene. [119] Within a reaction time of 100 min, CdS-Au-{010}BiVO 4 {110}-MnO x achieved 97.2% toluene degradation under solar irradiation, which was 17.5 times higher than thermal catalysis and photocatalysis combined.…”

Sulfur-Modified Nickel-Based Hybrid Nanosheet as a Robust Bifunctional Electrode for Hydrogen Generation via Formaldehyde Reforming

“…However, for the Ni­(OH) 2 material with intrinsically weak conductivity, the catalytic activity and potential application have been severely limited. Constructing an interfacial heterostructure to realize the synergistic optimization of the electronic structure and reaction kinetics of Ni­(OH) 2 is one of the important ways. − For example, structurally disordered β-NiOOH/β-Ni­(OH) 2 is developed on a Ni nanowire-based electrode. It shows promoted catalysis of formaldehyde oxidation due to the abundant surface catalytic active sites .…”