Tunable bismuth doping/loading endows NaTaO3 nanosheet highly selective photothermal reduction of CO2

Photothermal CO2 reduction with H2O, integrating advantages of photocatalysis driven H2O splitting and thermal catalysis promoted CO2 reduction, has drawn sharply increasing attention in artificial synthesis of solar fuels. The photothermal effect of metal nanoparticles facilities CO2 hydrogenation and activation of lattice oxygen in oxide photocatalyst promotes H2O oxidation, which is essentially considered for highly efficient photothermal catalysis. However, the large thermal conductivity of most metal nanoparticles induces inevitable heat dissipation, restricting the increase of catalyst temperature. In this work, to minimize the heat dissipation, we employ bismuth nanoparticles as photothermal unit, which is of the lowest thermal conductivity in the metal family. Meanwhile, we adopt bismuth doped NaTaO3 as photocatalytic unit because of the bismuth doping induced activation of lattice oxygen. The bismuth nanoparticles are assembled with bismuth doped NaTaO3 through one-step tunable transformation from Bi4TaO8Cl. Benefiting from the photothermal effect, thermal insulation caused by bismuth metal, and lattice oxygen activation by bismuth doping, the NaTaO3:Bi hybrid exhibits high photothermal catalytic performance. The yield of CO over NaTaO8:Bi hybrid at 413 K via photothermal catalysis is 141 times higher than that room temperature photocatalysis. Further, ultraviolet (UV) light irradiation leads to 89.2% selectivity of CO and visible light irradiation leads to 97.5% selectivity of CH4. This work may broaden the photocatalytic application of ABO(3) perovskite and provides a novel strategy for the development of photothermal catalysts for artificial photosynthesis.

Automated summary

Photothermal CO2 reduction with H2O, combining the advantages of photocatalysis driven H2O splitting and thermal catalysis promoted CO2 reduction, has attracted increasing attention in the synthesis of solar fuels. In this study, bismuth nanoparticles with low thermal conductivity were used as the photothermal unit, and bismuth doped NaTaO3 was used as the photocatalytic unit. The NaTaO3:Bi hybrid showed high photothermal catalytic performance due to the photothermal effect, thermal insulation by bismuth metal, and lattice oxygen activation by bismuth doping.