Selective CO(2) reduction to HCOOH on a Pt/In(2)O(3)/g-C(3)N(4) multifunctional visible-photocatalyst

Selective photocatalytic reduction of CO(2) has been regarded as one of the most amazing ways for re-using CO(2). However, its application is still limited by the low CO(2) conversion efficiency. This work developed a novel Pt/In(2)O(3)/g-C(3)N(4) multifunctional catalyst, which exhibited high activity and selectivity to HCOOH during photocatalytic CO(2) reduction under visible light irradiation owing to the synergistic effect between photocatalyst, thermocatalyst, and heterojunctions. Both In(2)O(3) and g-C(3)N(4) acted as visible photocatalysts, in which porous g-C(3)N(4) facilitated H(2) production from water splitting while the In(2)O(3) nanosheets embedded in g-C(3)N(4) pores favored CO(2) fixation and H adsorption onto the Lewis acid sites. Besides, the In(2)O(3)/g-C(3)N(4) heterojunctions could efficiently inhibit the photoelectron–hole recombination, leading to enhanced quantum efficiency. The Pt could act as a co-catalyst in H(2) production from photocatalytic water splitting and also accelerated electron transfer to inhibit electron–hole recombination and generated a plasma effect. More importantly, the Pt could activate H atoms and CO(2) molecules toward the formation of HCOOH. At normal pressure and room temperature, the TON of HCOOH in CO(2) conversion was 63.1 μmol g(−1) h(−1) and could reach up to 736.3 μmol g(−1) h(−1) at 40 atm.