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[Display omitted] • Photocatalytic degradation of toluene was promoted by oxygen vacancy on InOOH. • OVs also facilitated methyl oxidation with the enhanced selectivity for ring opening. • In situ DRIFTS dynamically tracked the formation of primary reaction intermediates. • The reaction mechanism involved in photocatalysis of toluene is elucidated. The potential of oxygen vacancies (OVs) has been demonstrated in controlling photocatalytic activities by altering the electronic and/or band structures of photocatalysts. The effects of oxygen vacancies on photocatalytic reaction processes are yet unclear. In this work, indium oxyhydroxide (InOOH), well known as a wide band p-block metal compound with OVs, was synthesized through a one-pot solvothermal method to explore the roles of OVs in photocatalytic oxidation and ring opening of toluene. The defect level introduced by OVs enhanced light absorption and charge carrier separation, while promoting the activation of reactants to generate active oxygen species. As such, the modified InOOH was validated to enhance the photocatalytic performance by lowering the reaction energy barrier of the key intermediates during toluene oxidation (relative to the pristine InOOH). More strikingly, the energy barrier for the formation of benzoic acid was reduced with the increasing number of OVs on InOOH (accompanied by the increases in the ring opening reaction rates), in line with the results derived from the in situ DRIFTS investigation and theoretical calculation. Accordingly, it is possible to explain the mechanism regulating the photocatalytic oxidation of toluene on defective InOOH. This work could provide an electronic insight into oxygen vacancy engineering as a new strategy to enhance the photocatalytic selectivity and activity for VOC degradation. [ABSTRACT FROM AUTHOR]

• Monodisperse Au nanoparticles@g-C 3 N 4 has been designed and fabricated. • The Au@CN exhibits higher photocatalytic NO removal efficiency. • The Au@CN could effectively suppress the toxic intermediate NO 2. • The reaction pathway of photocatalytic NO oxidation can be tuned. • Ideal electronic structure of Au@CN enables direct conversion of NO to nitrate. Oxidation of low-concentration nitrogen oxides (NO x) to nitrate with solar energy is an efficient way to remove them from atmospheric environment under semi-enclosed or ill-airflow conditions. However, conventional photocatalysts applied in NO x removal face the challenges of low efficiency and generation of toxic byproducts (nitrogen dioxide, NO 2) leading to secondary pollution. To tackle these issues, monodisperse gold nanoparticles supported on graphitic carbon nitride (Au@CN) was designed and fabricated by a facile method. The Au@CN exhibited a highly enhanced nitric oxide (NO) oxidation activity and superior NO 2 inhibition ability. The microstructures, optical properties and electronic structure of the photocatalysts were analyzed with advanced tools. The in situ diffuse reflectance infrared spectroscopy (DRIFTS) was applied to dynamically monitor and reveal the reaction process at time sequence. Density functional theory (DFT) and electron spin resonance (ESR) were combined to explore the oxidation mechanism at molecular level. It was found that (1) the presence of Au metal site favored the adsorption and activation of the gas molecules; (2) the high separation efficiency of the photogenerated electron-hole pairs enhanced the production of radicals for NO oxidation; (3) the unique electronic structure of Au@CN prefers nitrate formation with a low rate-determining barrier and largely suppress the toxic intermediate NO 2 , thus effectively controlling the secondary pollution. The present work could provide a novel mechanistic insight into visible-light photocatalytic NO oxidation and selectivity on Au@CN which is beneficial for designing efficient and safe photocatalyst with low environmental risk. [ABSTRACT FROM AUTHOR]

• Innovative tumor drug-resistant mechanistic research. • Innovative multifunctional bionic nanomaterial design. • Good biosafety, circulatory system stability, and tumor targeting ability. • Drug/Fenton-like reaction/low-temperature photothermal combined tumor killing. • Improvement of the immune microenvironment in chemo-resistant tumor. Given that the treatment of drug-resistant osteosarcoma is a significant clinical challenge, in drug-resistant tumors, the role of endothelial cells has been recently emphasized. We noted that heterogeneous vascular endothelial cells (ONHVECs) in drug-resistant osteosarcoma tissues may inhibit macrophage-mediated killing of tumor cells, thus promoting the occurrence of drug resistance. Accordingly, we designed a type of hybrid membrane-coated multifunctional nanoparticle (NP), SiO 2 @PDA/Fe3+@Cis@HM. The NPs had good biocompatibility and enhanced the occurrence of low-temperature photothermal Fenton-like reactions. The hybrid membrane endowed the NPs with a tumor homing ability and homologous cell targeting ability, thus simultaneously targeting drug-resistant tumor cells and ONHVECs, in addition to killing tumor cells via efficient delivery of cisplatin and ROS produced by accelerated Fenton-like reactions. Through in vivo and in vitro experiments, we confirmed that SiO 2 @PDA/Fe3+@Cis@HM NPs efficiently killed tumor cells as well as ONHVECs. The endogenous exosomes produced by damaged ONHVECs induced anti-tumor M1 macrophage polarization to indirectly kill tumor cells and achieve synergistic therapy. This immune regulation was completely inherent and exhibited consistent efficacy, without ethical connotations. In conclusion, this multifunctional treatment strategy is the first to adopt a tumor cell/vascular endothelial cell double-targeted concept, which realized the direct killing of drug-resistant tumor cells and a natural immune enhancement response and could become a new paradigm for the treatment of drug-resistant osteosarcoma. [ABSTRACT FROM AUTHOR]

A well-defined In 2 O 3 /InN heterojunction was developed for the electrocatalytic CO 2 reduction reaction to formate. The O-N interaction at the interface of In 2 O 3 /InN heterojunction promotes the charge transfer to activate CO 2 molecules, lower the Gibbs free energy for *HCOO formation and thus results in unprecedented high Faradaic efficiency (95.7% at −1.48 V vs. RHE) and outstanding stability. [Display omitted] • Pure In 2 O 3 or In 2 O 3 /InN heterostructure were obtained under different atmosphere. • The In 2 O 3 /InN catalyst exhibits enhanced FE formate (>95%) from −1.37 to −1.59 V. • The In 2 O 3 /InN heterojunction exhibits almost no degradation of performance after 30 h. • The O-N interaction at the interface of In 2 O 3 /InN heterojunction promotes charge transfer. • In situ ATR-SEIRAS and DFT were performed to reveal the electrocatalytic mechanism. Electrocatalytic reduction of CO 2 into value-added chemicals and fuels is of intensive urgence and importance to relieve the growing CO 2 emission and achieve the carbon neutrality. Herein, an In 2 O 3 /InN heterojunction was constructed and firstly utilized in electrocatalytic CO 2 reduction reaction (CO 2 RR) to formate with high Faradaic efficiency (95.7% at −1.48 V vs. RHE) and outstanding stability. The in-depth experimental analyses together with theoretical studies reveal that the O-N interaction at the interface between In 2 O 3 and InN could provide a charge transfer channel and lead to electron enrichment on the surface of InN, promoting the activation of CO 2 molecules, lowering the Gibbs free energy for the formation of *HCOO intermediate and strengthening the binding with *HCOO during CO 2 RR. This work provides a fundamental understanding of the interaction at In-based heterostructure interface for highly selective CO 2 reduction to formate and offers a universal route for the design of other type metal oxide/nitride heterostructures for various catalytic applications. [ABSTRACT FROM AUTHOR]

• The activation energies are ascertained for ROS generation and transformation. • The facet engineering of BiOCl photocatalyst benefits the NO x removal efficiency. • The generation of intermediate NO 2 is significantly suppressed. • Experimental and theoretical methods are combined to reveal the reaction mechanism. The generation and transformation of reactive oxygen species (ROS) is a key parameter in catalyzing photocatalytic gas-phase oxidation reactions for environmental remediation. Thus the determination, quantification and kinetic tracking of ROS are conclusively required to realize complete pollutant conversion and intermediates suppression. By quantifying the activation energies (E a) and ascertaining the rate-determining step (RDS), a panoramic understanding is established in ROS-induced NO x oxidation reactions. To be specific, the BiOCl photocatalyst with tailored facets were designed and fabricated as model catalysts. It is proposed that the ROS generation and transformation pathways are along the path of OH → H 2 O 2 → O 2 −, in which the H 2 O 2 dissociation is the RDS for O 2 − generation. Moreover, it is concluded that NO 2 is the primary intermediate in NO oxidation reaction, and the further transformation of NO 2 requires the highest E a among all the elementary reactions. Significantly decreased E a and suppressed NO 2 accumulation are realized on the {0 1 0} facet of BiOCl to achieve efficient NO x conversion. A new perspective is stated in this research to establish a comprehensive understanding between ROS generation mechanism and intermediates suppression for efficient NO x removal, which provides new insights into the application of photocatalysis technology for air pollution control area. [ABSTRACT FROM AUTHOR]