Improving the selectivity of photocatalytic NOx abatement through improved O2 reduction pathways using Ti0.909W0.091O2Nx semiconductor nanoparticles: from characterisation to photocatalytic performance

In this paper, we provide detailed insight into the electronic–crystallographic–structural relationship for Ti0.909W0.091O2Nx semiconductor nanoparticles, explaining the mutual electronic and magnetic influence of the photoinduced stable N- and W-based paramagnetic centers, their involvement in the photoinduced charge-carrier trapping, and their role in improving the nitrate selectivity of the photocatalytic oxidation of NOx to nitrates. In particular, reduced tungsten species in various crystallographic environments within the anatase host lattice were observed as playing a fundamental role in the storage and stabilization of photogenerated electrons. Here, we show how these reduced centers can catalyze multielectron transfer events without the need for rare and expensive platinum-group metals (PGMs). This allows for the versatile and elegant configuration of redox potentials. As a result, electron-transfer processes that are kinetically inaccessible with metal oxides such as TiO2 can now be accessed, en...