To eliminate nitrogen oxides (NOx), a series of highly ordered mesoporous WO3(χ)-CeO2 nanomaterials (χ represents the mole ratio of W/Ce) were synthesized by using KIT-6 as a hard template, which was used for selective catalytic reduction (SCR) to remove NOx with NH3 at low temperatures. Moreover, the nanomaterials were characterized by TEM, XRD, Raman, XPS, BET, H2-TPR, NH3-TPD and in situ DRIFTS. It can be found that all of the prepared mesoporous WO3(χ)-CeO2 (χ = 0, 0.5, 0.75, 1 and 1.25) showed highly ordered mesoporous channels. Furthermore, mesoporous WO3(1)-CeO2 exhibited the best removal efficiency of NOx, and its NOx conversion ratio could reach 100% from 225 ° C to 350 ° C with a gas hourly space velocity of 30 000 h−1, which was due to higher Ce3+ concentrations, abundant active surface oxygen species and Lewis acid sites based on XPS, H2-TPR, NH3-TPD and in situ DRIFTS. In addition, several key performance parameters of mesoporous WO3(1)-CeO2, such as superior water resistance, better alkali metal resistance, higher thermal stability and N2 selectivity, were systematically studied, indicating that the synthesized mesoporous WO3(1)-CeO2 has great potential for industrial applications.

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A highly efficient Z‐scheme photocatalytic system constructed with 1D CdS and 2D CoS2 exhibited high photocatalytic hydrogen‐evolution activity of 5.54 mmol h−1 g−1 with an apparent quantum efficiency of 10.2 % at 420 nm. More importantly, its interfacial charge migration pathway was unraveled: The electrons are efficiently transferred from CdS to CoS2 through a transition atomic layer connected by Co–S5.8 coordination, thus resulting in more photogenerated carriers participating in surface reactions. Furthermore, the charge‐trapping and charge‐transfer processes were investigated by transient absorption spectroscopy, which gave an estimated charge‐separation yield of approximately 91.5 % and a charge‐separated‐state lifetime of approximately (5.2±0.5) ns in CdS/CoS2. This study elucidates the key role of interfacial atomic layers in heterojunctions and will facilitate the development of more efficient Z‐scheme photocatalytic systems.

Fe3O4-TiO2 nanosheets (Fe3O4-TNS) were synthesized by means of lamellar reverse micelles and solvothermal method, which were characterized by TEM, XRD, XPS, BET, and magnetic property analysis. It can be found that Fe3O4-TNS nanosheets exhibited better photocatalytic antibacterial activity toward Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus than pure Fe3O4 and TNS, and the antibacterial efficiency could reach 87.2% and 93.7% toward E. coli and S. aureus with 100 μg/mL Fe3O4-TNS after 2 h of simulated solar light illumination, respectively. The photocatalytic destruction of bacteria was further confirmed by fluorescent-based cell live/dead test and SEM images. It was uncovered that Fe3O4-TNS inactivated G- E. coli and G+ S. aureus by different mechanisms: the destruction of outer membranes and ruptured cell bodies were responsible for the bactericidal effect against E. coli, while the antibacterial effect toward S. aureus were due to the fact that the cells were adsorbed in form of clusters by massive Fe3O4-TNS, which could restrict their activities and cause malfunction of the selective permeable barriers. Furthermore, the antibacterial mechanism was studied by employing scavengers to understand exact roles of different reactive species, indicating the key roles of h(+) and H2O2. The recovery and reusability experiments indicated that Fe3O4-TNS still retained more than 90% bacteria removal efficiency even after five cycles. Considering the easy magnetic separation, bulk availability, and high antibacterial activity of Fe3O4-TNS, it is a promising candidate for cleaning the microbial contaminated water environment.

Methane partial oxidation (MPO) chemically transforms natural gas into syngas for the production of gasoline. CeO2 doped with transition-metal ions is one type of catalyst active for MPO. A fundamental understanding of MPO on this type of catalyst is important for the development of catalysts with high activity and selectivity for this process. CeO2-based catalysts, including Pd-CeO2-air, Pd-CeO2-H2, Pt-CeO2-air, Pt-CeO2-H2, Rh-CeO2-air, and Rh-CeO2-H2, were synthesized through doping noble-metal ions in the synthesis of CeO2 nanoparticles. The catalytic activity and selectivity in the production of H2 and CO through MPO on these ceria-based catalysts as well as their surface chemistries during catalysis were investigated. They exhibit quite different catalytic performances in MPO under identical catalytic conditions. In situ studies of their surface chemistries during catalysis, using ambient-pressure X-ray photoelectron spectroscopy (AP–XPS), revealed quite different surface chemistries during catalysis. Correlations between the catalytic performances of these catalysts and their corresponding surface chemistries during catalysis were developed. Differing from the other four catalysts, Rh doped in the surface lattice of a CeO2 catalyst, including Rh-CeO2-air and Rh-CeO2-H2, is in a complete ionic state during catalysis. Correlations between the in situ surface chemistry and the corresponding catalytic performance show that Rh ions and Pt ions doped in the lattice of CeO2 as well as metallic Pd nanoparticles supported on CeO2 are active components for MPO. Among these catalysts, Rh-doped CeO2 exhibited the highest catalytic activity and selectivity in MPO.