Enhanced Gas-Phase pollutant removal using Pt nanoparticle-modified exfoliated carbon nitride photocatalysts under UV and visible light

• Graphitic carbon nitride’s tunability and light absorption make it ideal for environmental air pollution remediation. • Platinum nanoparticles on carbon nitride achieve 85 % trichloroethylene conversion under visible light. • Volatile Organic Compounds can be decomposed under low-power visible light irradiation. • Materials present high stability under the chosen operating conditions. Platinum nanoparticles (Pt NPs) have been prepared by the organometallic approach on the surface of exfoliated graphitic carbon nitride (exf-g-CN) with different metal loadings. Multi-technique characterization shows a good dispersion of Pt NPs on the surface of exf-g-CN with a narrow size distribution between 1.7–2.2 nm and a BET area of about 120 m 2 /g. The Pt NPs are mainly composed of platinum metal with a minor contribution of oxidic surface species. The effect of UV-A and Vis light of different wavelengths on the photocatalytic performance is investigated. The as-prepared hybrid materials show excellent photocatalytic activity for the decontamination of air from volatile organic compounds (VOCs, in particular trichloroethylene, C 2 HCl 3 ) under low power visible light irradiation. The conversion value reaches a maximum close to 85 % at 405 nm Vis light for 0.5 wt.% Pt loading. At this level of Pt content, electron and hole recombination rates are suppressed according to photoluminescence analysis. Photonic efficiencies of around 0.3 % were achieved under Vis light. The optimised material shows high stability from 2,500 min of operation. XPS analysis suggests the crucial role of Pt/Pt 2+ and chlorine species detected on used samples in the reaction rate and stability of the material.