Silver embedded in defective twin brush-like ZnO for efficient and stable photocatalytic NO removal

Abstract

Solar photocatalysis is a clean and sustainable approach for removing atmospheric NO, but suffers from unsatisfactory removal efficiency. Efficient charge separation and surface reaction are critical factors ensuring the efficiency of solar energy conversion by photocatalysts. To achieve efficient charge steering and an enhanced surface reaction, we synthesized a bicomponent photocatalyst consisting of multivalent Ag species embedded in defect-rich twin-brush ZnO (Ag/TB-ZnO) with strong metal-support interaction (SMSI). The optimum Ag/TB-ZnO with silver loading of 2.0 wt.% achieved NO oxidation efficiency of 71.0% under a GHSV of 1,200,000 mL h−1 g−1, and NO3− selectivity of 94.8%. Outstanding stability of up to 4 h was demonstrated. This superior performance was attributed to the enhanced efficacy of charge separation and surface reaction by the SMSI effect, surface plasmon resonance effect of metallic Ag and the efficient activation of oxygen species through vacancy-rich TB-ZnO.