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Developing economic and high-performance noble metal-free photocatalysts is the key to realize efficient photocatalysis. In this work, NiS nanoparticles and hierarchical Sn3O4 nanostructures are tightly bonded by a two-step method combining hydrothermal and ion precipitation to construct a 0D/3D nanocomposite structure, which accelerates the interface electron transfer rate and photogenerated electron–hole separation efficiency. Compared with the pure Sn3O4, the loaded samples obviously have stronger light absorption capacity and effectively improve the utilization of visible light, thus showing enhanced photocatalytic hydrogen generation performance. NiS provides more active sites on the surface and facilitates electron transit as an electron acceptor, resulting in increased photocatalytic activity. As a result, when the loading of NiS reaches 1.0%, the photocatalyst shows an excellent hydrogen production performance, with an average hydrogen generation rate of 17.43 μmol g−1 h−1, which is 2.4 times than that of the pristine Sn3O4. This research offers a new idea to develop noble metal-free photocatalysts with high activity. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrite (NO 2 - ) reduction to ammonia (NH 3 ) is a promising method for reducing pollution and aiding industrial production. However, progress is limited by the lack of efficient selective catalysts and ambiguous catalytic mechanisms. This study explores the loading of PdCu alloy onto oxygen defective TiO 2-x , resulting in a significant increase in NH 3 yield (from 70.6 to 366.4 µmol cm -2  h -1 at -0.6 V vs reversible hydrogen electrode) by modulating localized electron density. In situ and operando studies illustrate that the reduction of NO 2 - to NH 3 involves gradual deoxygenation and hydrogenation. The process also demonstrated excellent selectivity and stability, with long-term durability in cycling and 50 h stability tests. Density functional theory (DFT) calculations elucidate that the introduction of PdCu alloys further amplified electron density at oxygen vacancies (Ovs). Additionally, the Ti─O bond is strengthened as the d-band center of the Ti 3d rising after PdCu loading, facilitating the adsorption and activation of * NO 2 . Moreover, the presence of Ovs and PdCu alloy lowers the energy barriers for deoxygenation and hydrogenation, leading to high yield and selectivity of NH 3 . This insight of controlling localized electron density offers valuable insights for advancing sustainable NH 3 synthesis methods., (© 2024 Wiley‐VCH GmbH.)

Responsible development of nanotechnology calls for improved understanding of how nanomaterial surface energy and reactivity affect potential toxicity. Here, we challenge the paradigm that cytotoxicity increases with nanoparticle reactivity. Higher-surface-energy {001}-faceted CdS nanorods (CdS-H) were less toxic to Saccharomyces cerevisiae than lower-energy ({101}-faceted) nanorods (CdS-L) of similar morphology, aggregate size, and charge. CdS-H adsorbed to the yeast's cell wall to a greater extent than CdS-L, which decreased endocytosis and cytotoxicity. Higher uptake of CdS-L decreased cell viability and increased endoplasmatic reticulum stress despite lower release of toxic Cd(2+) ions. Higher toxicity of CdS-L was confirmed with five different unicellular microorganisms. Overall, higher-energy nanocrystals may exhibit greater propensity to adsorb to or react with biological protective barriers and/or background constituents, which passivates their reactivity and reduces their bioavailability and cytotoxicity.