Efficient Assembly of a Rare Earth-Indium Bimetallic Vanadate/g-C3N4 Heterojunction for Enhanced Uranium(VI) Visible-Light Photocatalytic Separation

A ternary rare earth-indium bimetallic vanadate/g-C 3 N 4 heterojunction (MVG) was constructed by using a simple in situ self-assembly technique to solve the increasingly serious problem of uranium(VI)-containing wastewater pollution. MVG, especially MVG-IN, exhibited good photocatalytic U(VI) reduction separation activity, which demonstrated its good potential for U(VI)-containing wastewater remediation. MVG-IN obtained by using a combination of NdVO 4, InVO 4, and g-C 3 N 4 to construct multiple heterojunctions exhibited a uniform porous structure and good visible-light response. The good interfacial U(VI) adsorption activity of MVG-IN gave it a high adsorption capacity (693.6 mg·g –1 ) in a dark environment. MVG-IN with high equilibrium U(VI) separation efficiency (98.9%) could separate over 90% of U(VI) after 30 min of illumination. Moreover, MVG-IN also had good resistance to ion interference and could maintain a separation efficiency of over 85% after four cycles. The photocatalytic U(VI) reduction separation mechanism of MVG-IN indicated that the synergistic effect of the high interfacial U(VI) adsorption activity and visible-light response brought by the formation of multiple heterostructures endowed MVG-IN with good photocatalytic U(VI) reduction separation activity. This work might be expected to provide assistance for the development of photocatalyst materials with high photoresponsive and U(VI) reduction separation performance.