Built-in electric field intensified by photothermoelectric effect drives charge separation over Z-scheme 3D/2D In_(2)Se_(3)/PCN heterojunction for high-efficiency photocatalytic CO_(2) reduction

It is a challenging issue to further drive charge separation through the oriented design of Z-scheme het-erojunction in the exploitation of cost-effective photocatalytic materials.In this contribution,the unique Z-scheme 3D/2D In_(2)Se_(3)/PCN heterojunction is developed through implanting In_(2)Se_(3) microspheres on PCN nanosheets using an in situ growth technique,which acquires the effective CO generation activity from photocatalytic CO_(2) reduction(CO_(2)R).The CO yield of 4 h in the CO_(2)R reaction over the optimal In_(2)Se_(3)/PCN-15 sample reaches up to 11.40 and 2.41 times higher than that of individual PCN and In_(2)Se_(3),respectively.Such greatly enhanced photocatalytic performance is primarily the improvement of photo-generated carrier separation efficiency.To be more specific,the formed built-in electric field is signifi-cantly intensified by producing the temperature difference potential between In_(2)Se_(3) and PCN owing to the photothermoelectric effect of In_(2)Se_(3),which actuates the high-efficiency separation of photogenerated charge carriers along the Z-scheme transfer path in the In_(2)Se_(3)/PCN heterojunction.The effective strat-egy of enhancing the built-in electric field to drive photogenerated charge separation proposed in this work opens up an innovative avenue to design Z-scheme heterojunction applied to high-efficiency pho-tocatalytic reactions,such as hydrogen generation from water splitting,CO_(2)R,and degradation of organic pollutants.