Photothermally induced defect engineering: boosting photothermal synergistic selective catalytic oxidation of benzyl alcohol over in situ oxygen vacancy-modulated ultrathin ZnTi-LDH nanosheet

Abstract

The coordination and activation of C–O bonds into high-value-added CO bond products are significant and sustainable processes. Nevertheless, most researchers have focused on converting C–O bonds either through green photocatalysis or industrial thermocatalysis independently. The coordination and activation of C–O bonds via defect engineering, particularly stimulated by the emerging photothermal synergy effect, remain less explored. Herein, we investigate the photothermal effect-induced construction of oxygen vacancies (OVs) with varying concentrations on ultrathin ZnTi-LDH nanosheets (denoted as ZT-25, ZT-50, and ZT-70; T = 25, 50, and 70 °C, respectively) for the selective oxidation of benzyl alcohol under visible light irradiation. Extensive experimental characterization and theoretical calculations jointly indicate that ultrathin ZnTi-LDH nanosheets can produce more coordinatively unsaturated OVs with the increase in reaction temperatures. These OV active sites can achieve the coordination and activation of benzyl alcohol effortlessly. The ZT-70 sample shows a 57.78% conversion efficiency for the photothermal oxidation of benzyl alcohol, higher than that achieved by ZT-25 (44.40%). The elevated performance is attributed to the abundant OV active sites and optimal transfer of photothermally induced charges. This work presents a green strategy to achieve the activation of C–O bonds for benzyl alcohol oxidation via defect engineering induced by the photothermal synergy effect.