In-situ construction of bifunctional MIL-125(Ti)/BiOI reactive adsorbent/photocatalyst with enhanced removal efficiency of organic contaminants

Abstract

Employing green and efficient technology to remove contaminants remains to be exploited. Adsorption and photocatalysis are deemed to overcome this issue. In this work, MIL-125(Ti)/BiOI nanocomposite were synthesized via a moderate solvothermal treatment and employed for the adsorption and degradation of rhodamine B (RhB) and tetracycline (TC) from water. The combination of high surface reactivity of MIL-125(Ti) with photoactivity of BiOI result in i) quick reactive adsorption of RhB and TC and ii) succeeding photodegradation of RhB and TC. The maximum adsorption capacity of RhB and TC could reach 89.49 mg g−1 and 67.29 mg g−1 over 20 wt% MIL-125(Ti)/BiOI, much higher than BiOI and MIL-125(Ti). And the kinetic rate constants of RhB and TC degradation were approximately 21.6 and 3.3 times than single BiOI. The Ti3+-Ti4+ intervalence electron transfer and favourable interface contact are responsible for highly improved charge separation efficiency, which contribute to the enhancement of photocatalytic efficiency. Our research extends the knowledge into constructing bifunctional nanocomposite with considerable potential application for abatement of various organic contaminants.