Atomically mixed catalysts on a 3D thin-shell TiO₂ for dual-modal chemical detection and neutralization

Environmental pollutants threaten millions of lives and state-of-the-art strategies, mostly based on surface catalytic activities to remediate environmental issues, have emerged. Despite their active capabilities, traditional schemes are only capable of a single function, either sensing hazardous chemicals or their reduction, limiting the identification of clear solutions to environmental problems. This study proposes a material engineering method that adopts both the detection and neutralization of environmental pollutants for remediation. This strategy exploits ultrafast flash lamp-driven thermal engineering to realize ultra-small (<5 nm) polyelemental nanoparticles with a uniform size distribution on a three-dimensional (3D) metal oxide nanostructure. Specifically, an intense pulse light treatment on highly periodic 3D thin-shell TiO2 triggers an intensive photothermal effect, enabling instant reduction of various surface-decorated metal ion precursors into an atomically mixed heterostructure. Experimental and computational studies were conducted to investigate the physicochemical reactions occurring on the heterometal catalysts. As a proof-of-concept, the universal photocatalytic utility of dual-mode photoactivated quaternary phase (PtPdNiCo) NPs incorporated into 3D TiO2 was demonstrated for gaseous chemical sensing and degradation of environmental pollutants in water.