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The effective activation and utilization of O2have always been the focus of scientists because of its wide applications in catalysis, organic synthesis, life and medical science. Here, a novel method for activating O2spontaneously via interfacial oxygen vacancies on carbon-coated TiO2–xto generate reactive oxygen species (ROS) with versatile applications is reported. The interfacial oxygen vacancies can be stabilized by the carbon layer and hold its intrinsic properties for spontaneous oxygen activation without light irradiation, while common surface oxygen vacancies on TiO2–xare always consumed by the capture of H2O to form the surface hydroxyls. Thus, O2absorbed at the interface of carbon and TiO2–xcan be directly activated into singlet oxygen (1O2) or superoxide radicals (·O2–), confirmed both experimentally and theoretically. These reactive oxygen species exhibit excellent performance in oxidation reactions and inhibition of MCF-7 cancer cells, providing new insight into the effective utilization of O2via oxygen vacancies on metal oxides.

The synergistic photocatalytic Fenton reaction is a powerful advanced oxidation technique for the degradation of persistent organic pollutants. However, microwave-induced thermal effects on the formation of novel structures facilitating the photocatalytic degradation have been rarely reported. Herein, a two-step microwave thermal strategy was developed to synthesize a new hybrid catalyst comprising defective WO3–xnanowires coupled with reduced graphene oxides (rGOs). Conventionally, microwave methods could induce superhot spots on the GO surface, resulting in the site-specific crystallization and oriented growth of WO3. However, in the solid phase, localized microwave thermal effects could reduce the interfacial area between WO3and rGO and enhance the bonding between them. As for the unique structure and surface properties, the synthesized catalyst enhanced the light absorption, promoted the interfacial charge separation, and increased the carrier density in the photocatalytic processes. In addition, surface formation of W4+provided a new pathway for Fe3+/Fe2+cycling which linked the photocatalytic reaction and the Fenton process. The optimized catalyst exhibited a remarkable performance in the degradation of bisphenol A with a ∼83% removal yield via a photo-Fenton route. These microwave-induced functionalities of materials for synergistic reactions could also give a new avenue to other photoelectrocatalytic fields and solar cells.

Heterogeneous organometallic catalysts with well-defined active sites and hierarchical pores hold tremendous promise for efficient and eco-friendly chemical processes. However, the simple and scalable preparation of these materials remains difficult to date, which has hampered a more broad application scope. Herein, we reported a low-cost, rapid, and scalable aerosol-assisted assembly approach for the synthesis of a well-defined PdDPP (PdCl2(PPh2(CH2)2))_ complex-containing benzene-bridged organosilica-based catalyst with a hierarchical bimodal micro-macroporous structure. This novel material was realized by using Pd(II) organometallic silane (Pd[PPh2(CH2)2Si(OEt)3]2Cl2) as the active species, organosilane 1,4-bis(triethoxysilyl)benzene (Ph[Si(OEt)3]2) as the silicate scaffold and the surfactant cetyltrimethylammonium bromide and the inorganic salt NaCl as the dual templates on a home-built aerosol spraying-instrument. Multiple techniques including X-ray photoelectron spectroscopy and solid-state NMR spectra revealed that the organopalladium complex with a well-defined molecular configuration of major trans model and minor cis model existed in the phenyl-functionalized silica material. As expected, it efficiently promoted a variety of important carbon–carbon cross-coupling transformations including Tsuji–Trost, Sonogashira, and Suzuki reactions in pure water without the assistance of any additives. In comparison with the homogeneous catalyst PdCl2(PPh2CH3)2, it even exhibited enhanced activity and selectivity in some cases owing to the unique confinement effect and the shape selectivity generated from the hierarchical porous structure. Meanwhile, it was easily recycled and reused eight times without the loss of its activity.

Oxygen reduction and evolution reactions (ORR and OER, respectively) are vital steps for metal–air batteries, which are plagued by their sluggish kinetics. It is still a challenge to develop highly effective and low-cost non-noble-metal-based electrocatalysts. Herein, a simple and reliable method was reported to synthesize a Co2P-assisted Co single-atom (Co–N4centers) electrocatalyst (Co2P/Co-NC) via evaporative drying and pyrolysis processes. The Co2P nanoparticles and Co–N4centers are uniformly distributed on the nitrogen-doped carbon matrix. Notably, Co2P/Co-NC showed excellent activities in both ORR (initial potential, 1.01 V; half-wave potential, 0.88 V) and OER (overpotential, 369 mV at 10 mA cm–2). The above results were comparable to those of commercial catalysts (such as Pt/C and RuO2). Based on the experimental and theoretical analyses, the impressive activity can be ascribed to the tailored electronic structure of Co–N4centers by the adjacent Co2P, enabling the electron transfer from the Co atom to the neighboring C atoms, leading to a downshift of the d-band center, and improved reaction kinetics were achieved. The assembled Zn–air batteries using Co2P/Co-NC as the air cathode showed a peak power density of 187 mW cm–2and long-life cycling stability for 140 h at 5 mA cm–2. This work may pave a promising avenue to design hybrid bifunctional electrocatalysts for highly efficient ORR/OER.

This work reports a moderate round-the-clock route to treating organic pollutants by utilizing a La2NiO4hollow-sphere microreactor. A glycerol-assisted solvothermal route followed by an annealing process was applied for fabricating the catalyst. Both the physicochemical properties and the catalytic performance of the as-obtained microreactor for treating pollutants were discussed. The microreactor exhibited a strong ability to degrade phenol and anionic dyes in the absence of light irradiation, owing to its high surface area and positively charged surface. With the aid of visible-light irradiation, the degradation rate of the organic pollutants could be further accelerated due to the light multireflection in a hollow structure, which enhances the utilization of light. The present work indicates that the hollow-sphere La2NiO4microreactor is effectively energy saving for environmental remediation.

Pt-doped mesoporous Ti3+self-doped TiO2(Pt–Ti3+/TiO2) is in situsynthesized via an ionothermal route, by treating metallic Ti in an ionic liquid containing LiOAc, HOAc, and a H2PtCl6aqueous solution under mild ionothermal conditions. Such Ti3+-enriched environment, as well as oxygen vacancies, is proven to be effective for allowing the in situreduction of Pt4+ions uniformly located in the framework of the TiO2bulk. The photocatalytic H2evolution of Pt–Ti3+/TiO2is significantly higher than that of the photoreduced Pt loaded on the original TiO2and commercial P25. Such greatly enhanced activity is due to the various valence states of Pt (Ptn+, n= 0, 2, or 3), forming Pt–O bonds embedded in the framework of TiO2and ultrafine Pt metal nanoparticles on the surface of TiO2. Such Ptn+–O bonds could act as the bridges for facilitating the photogenerated electron transfer from the bulk to the surface of TiO2with a higher electron carrier density (3.11 × 1020cm–3), about 2.5 times that (1.25 × 1020cm–3) of the photoreduced Pt–Ti3+/TiO2sample. Thus, more photogenerated electrons could reach the Pt metal for reducing protons to H2.

Fullerene (C60)-enhanced Bi2TiO4F2hierarchical microspheres were prepared by a facile solvothermal method. Compared to the pure Bi2TiO4F2photocatalyst, the C60/Bi2TiO4F2samples exhibit much stronger photocatalytic performance for degrading Rhodamine B (RhB) and Eosin Y (EY) under visible light irradiation. Such greatly enhanced photocatalytic activity may be ascribed to strong combination and heterojunctions between C60and Bi2TiO4F2, favorable for charge separation and light adsorption. Loading C60on Bi2TiO4F2results in a new photocatalytic mechanism (based on photo-generated hvb+and ·O2-radicals) different from that of pure Bi2TiO4F2.

With the rapid development of triboelectric nanogenerators (TENGs) for flexible wearable devices and electronic skins, challenges have gradually emerged related to the electrification surface, such as pollutant contamination and sophisticated surface adaptability. Hence, we report a simple spraying method to produce a shape-adaptive photocatalytic (SAP) triboelectric material with both self-cleaning and shape-adaptive functions. By spraying the polyvinyl alcohol solution with TiO2photocatalysts and pre-drying cyclic, the SAP film can be adapted to a varied and intricate substrate. The highest transferred charge density of the SAP film reaches 197.5 μC/m2, when it contacts with the PTFE film. At the same time, it can degrade 74.4% of simulated pollutants under sunlight illumination, and 97% of the transferred charge density can be maintained after the degradation process, indicating good self-cleaning function and stable electrical output. Moreover, the spraying method of this allows it to have shape-adaptive functions. Accordingly, the SAP film can be deposited on the rectangular pyramid and hemispherical surface for fabricating TENGs with special shapes. This low-cost and simple spraying method further promotes the commercialized application of TENGs in the field of wearable devices and skin sensors.