Donor-Acceptor characteristic g-C3N4 hollow nanospheres heterojunctions for efficient photocatalytic uranium reduction

Using photocatalysis to extract uranium from aqueous solution is a promising technique for the remediation of radioactive wastewater. This article reports the synthesis of hollow spherical g-C3N4 (HCN) via a template method, and its subsequent modification by PEDOT:PSS (PTPS) to form a donor-acceptor (D-A) heterojunction photocatalyst (PTPS@HCN). The well-designed hollow structure and the incorporation of PTPS enhanced the visible light absorption, effectively driving the separation and transfer of photogenerated charge carriers. Moreover, the theoretical calculation reveals that the electronic excitation model of PTPS@HCN exhibits a distinct charge-transfer excitation characteristic. As a result, PTPS@HCN could efficiently remove 98.6% of U(VI) after 90 min irradiation, which was 6.4 times higher than that of the pristine HCN. This study offers a new perspective for designing D-A organic photocatalysts for the photocatalytic separation of uranium.