A 3D C@TiO₂ multishell nanoframe for simultaneous photothermal catalytic hydrogen generation and organic pollutant degradation

Rapid heat loss and fast charge carrier recombination constitute two crucial issues that hinder the development of efficient solar energy utilization and conversion over the semiconductor in a photothermal catalytic system. Inspired by energy production from waste water, we designed an advanced 3D C@TiO₂ multishell nanoframe (MNF) photocatalyst. Its unique structural features of heat confinement and vibrant photocarrier kinetics lead to excellent photo-thermal conversion for synchronous superior photocatalytic H₂ evolution (503 μmol g^-1h^-1) and 98.2% RhB removal without the use of any co-catalyst and sacrificial reagent under simulated sunlight irradiation (AM 1.5G). Mechanism exploration reveals that the difference between the inner and outer gas pressure formed inside C@TiO₂ precursor facilitates the selective cleavage of outer TiO₂ layers at selected temperatures during calcination. Synergistic effects between residual carbon core and multi-shelled TiO₂ framework endow C@TiO₂ MNF with excellent heat confinement and vibrant photocarrier kinetics. Such MNF photo-thermocatalyst concept provides a novel strategy for effective utilization of solar energy, and this work may open a novel avenue towards advanced nanostructures for efficient waste-to-energy conversion.