Bifunctional TiO2/CeO2 reactive adsorbent/photocatalyst for degradation of bis-p-nitrophenyl phosphate and CWAs

Abstract

TiO2/CeO2 nanocomposites were prepared by simple refluxing of peroxo titanium and cerium complexes in water at ambient air and they were used for degradation of several organophosphorus compounds (OPC). The combination of high surface reactivity of ceria with photoactivity of titania led to i) rapid reactive adsorption of bis-p-nitrophenyl phosphate (BNPP) forming p-nitrophenyl phosphate (NP) and ii) subsequent photo-induced degradation of both BNPP and NP. The composites were also three and four times more efficient for rapid degradation of chemical warfare agents (CWAs) soman and VX in nonane compared to bare ceria and titania, respectively. The strong interaction of Ti with Ce within the composites led to the formation of Ce3+ and Ti<4+ states, reduction of titania crystallite size, change of acid-base and surface properties and synergetic effects that are all responsible for highly improved degradation efficiency of these bifunctional nanocomposites with considerable potential of application for abatement of various toxic compounds.