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Highly-efficient CeO2-TiO2-based catalyst is an attractive alternative to traditional V2O5-based catalysts for selective catalytic reduction of NOx by NH3 (NH3-SCR). Herein, we construct an efficient and stable P-doped CeO2/TiO2 (yCeTi-Px) catalyst by dispersing CeO2 on strongly acidic and highly stable mesoporous P-doped TiO2 (Ti-Px). The characteristic structure of Ti-Px causes highly dispersed CeO2, strong active component-support interaction, and abundant surface active oxygen and acid sites on CeTi-P catalyst. Therefore, yCeTi-Px catalyst exhibits much higher catalytic activity than yCeTi catalyst at temperature of 200–450 °C. The yCeTi-Px catalysts show high activity in the presence of H2O and strong resistance to H2O + SO2 at medium-high temperature, implying that they have great industrial application prospects. Different P/Ti ratio and CeO2 loading content were investigated. Excessive P doping can block the Ce4+/Ce3+ redox couple, and suppress redox sites on yCeTi-Px catalyst. Additionally, increasing CeO2 content can reduce the NH3 capacity of yCeTi-Px catalyst. By controlling the P/Ti ratio and CeO2 loading content, surface acid sites and redox sites on yCeTi-Px catalyst can be balanced to obtain the best catalytic activity. This work demonstrates a feasible method in adjusting acid sites and redox sites on CeTi catalyst, which ultimately contributes to the new design of CeO2-TiO2-based catalyst.

Membrane fouling caused by natural organic matters such as humic acid has been one of the major obstacles inhibiting the wide application of membrane technologies for water treatment. In this work, a novel membrane made of interconnecting TiO 2 nanowires, Fe 2 O 3 nanoparticles, and graphene oxide (GO) sheets was prepared via a simple hydrothermal, colloidal blending, and vacuum filtration method. Membrane performance of humic acid removal under simulated solar irradiation and in the dark were compared for membranes with different Fe 2 O 3 /TiO 2 /GO compositions. It was demonstrated that enhanced humic acid removal was achieved due to the greater adsorption of humic acid by Fe 2 O 3 nanoparticles and the improved photocatalytic activity of TiO 2 by the GO sheets that can facilitate separation of photo-induced electron-hole. An optimal Fe 2 O 3 :TiO 2 :GO weight ratio of 50:100:10 was identified, and over 98% humic acid removal was achieved in a short-term test (2 h) and 92% removal in a 12 h test under solar irradiation. By contrast, only 51% humic acid removal was obtained by the same membrane in dark in the 12 h test. A lower pressure drop across the membrane was also observed under solar irradiation (20 kPa) compared with that in the dark (50 kPa). This nanomaterial-based novel membrane contributes to the development of a more effective water treatment technology.