Rational design of versatile 1D Ti-O-based core-shell nanostructures for efficient pollutant removal and solar fuel production

Abstract

The rational design of Ti-O-based nanocomposites is of great importance for achieving efficient solar energy conversion and storage. Herein, novel one-dimensional (1D) K2Ti6O13/TiO2 core-shell nanobelt composites were fabricated by a controlled hydrothermal method using 1D K2Ti6O13 nanobelts as precursors. The K2Ti6O13 derived TiO2 shells with thickness of 5 nm were in-situ grown on the K2Ti6O13 NBs with closely connected interfaces, which resulted in remarkably enhanced photoactivities for pollutant degradation, hydrogen production and CO2 reduction. Interestingly, the porous carbon paper supported photocatalysts could be used for pollutant removal via synergistic adsorption and photothermal catalysis. Moreover, such a 1D core-shell nanobelt photoanode also showed higher photoelectrochemical water-splitting performance than pure K2Ti6O13, and impressively the significantly accelerated and stable H2 production was achieved due to the presence of thermodynamically favorable glycerol oxidation reaction. Importantly, the high value-added formate was produced along with cathodic H2 generation, revealing a sustainable way for concurrent solar hydrogen generation and green biomass upgrading. It was demonstrated that the enhanced photoactivities of K2Ti6O13/TiO2 nanocomposites could be mainly attributed to their higher light absorption, increased surface reactive sites and especially the promoted charge separation over the S-scheme heterojunction. This work paves a new avenue to rationally design versatile and high-performance Ti-O-based nanostructure photocatalysts for environmental remediation and solar fuels production.