Fabrication of Direct Z-Scheme CoNiWO 4 /Ph-gC 3 N 4 Heterocomposites: Enhanced Photodegradation of Bisphenol A and Anticancer Activity.

Photocatalysis is realized by the design of a visible-light-active catalyst with robust redox capacity and broad absorption. In this study, a series of novel Z-scheme CoNiWO 4 /Ph-gC 3 N 4 photocatalysts are synthesized to improve their redox property and photocatalytic activity toward broad visible light absorption. An intimate stable heterojunction is made between cobalt-nickel tungstate (CoNiWO 4 ) and phenyl-doped graphitic carbon nitride (Ph-gC 3 N 4 ), and its physicochemical properties are studied. The bifunctional properties of all of the synthesized materials were assessed by studying the decomposition of bisphenol A (BPA) and methyl orange (MO) dye as model pollutants, followed by an evaluation of their anticancer activity on human lung cancer cell lines. The photocatalyst with 20 wt % CoNiWO 4 heterocomposite showed an enhanced response toward the removal of cancerous cells. The synthesized pristine CoNiWO 4 and Ph-gC 3 N 4 exhibit well-matched band structures and, hence, make it easier to create a Z-scheme heterocomposite. This may increase the lifetime of photoinduced charge carriers with a high redox power, thereby improving their photocatalytic and anticancer activity. An extensive analysis of the mechanism demonstrates that hydroxyl radicals ( • OH) and superoxide radical anions ( • O 2 - ) are responsible for the degradation of organic compounds via Z-scheme charge transfer approach. These findings point toward a new route for creating effective Co-Ni tungstate-based direct Z-scheme photocatalysts for various redox processes, particularly the mineralization of resistant organic molecules.