Epitaxial-grafting strategy to boost inert hydroxide photocatalytic performance: A case study of SnOx-MgSn(OH)6

To utilize -OH on the inert hydroxides, a layer of photoactive SnOx was epitaxially grafted on MgSn(OH)6 (MgHS) by controlling the hydrothermal solution at ca. pH 4. SnOx shows a strong interaction with MgHS and acts as photoactive sites to provide photoinduced electrons (e-) and holes (h+), while the host provides a hydroxyl-rich surface to strengthen and sustain ∙OH-mediated degradation process. Furthermore, both the transferring of photoinduced h+ from SnOx to MgHS and the adsorption of benzene (C6H6) on MgHS were promoted by SnOx. The synergistic effect between SnOx and MgHS is responsible for the high and stable performance for abating bisphenol A solution and gaseous C6H6 exhaust. ∙OH and protonated O2∙- are the main active species. This work demonstrated that the epitaxial-grafting of photoactive metal oxides on a host hydroxide photocatalyst is a promising strategy to boost the photocatalytic performance of inert hydroxide photocatalysts for environmental remediation.