Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is of considerable importance for the industrial production of green and sustainable energy. Here, an ultrathin Ir-Sb nanowires ( Ir-Sb NWs) protected by antimony oxides (SbO_x) was synthesized as an efficient bifunctional catalyst for both HOR and HER under alkaline media. Except from the much higher mass activities of Ir-Sb nanowires than those of Ir nanowires (Ir NWs) and commercial Pt/C, the SbO_x protective layer also contributes to the maintenance of morphology and anti-CO poisoning ability, leading to the long-term cycling performance in the presence of CO. Specifically, the Ir-Sb NW/SbO_x exhibits the highest catalytic activities, which are about 3.5 and 4.8 times to those of Ir NW/C and commercial Pt/C toward HOR, respectively. This work provides that the ultrathin morphology and H₂O-occupied Sb sites can exert the intrinsic high activity of Ir and effectively optimize the absorption of OH* both in alkaline HER/HOR electrolysis.

TiO₂ is a promising photocatalyst due to its high thermodynamic stability and non-toxicity. However, its applications have been still limited because of the high recombination rate of electron–hole pairs. Herein, we show that by combining heterojunction construction and electronic structure regulation, the electron–hole pairs in TiO₂ can be effectively separated for enhanced photocatalytic hydrogen evolution. The optimized Cu₇S₄ nanosheet decorated TiO₂ achieves much enhanced H₂ evolution rate (11.5 mmol·g⁻¹·h⁻¹), which is 13.8 and 4.2 times of that of TiO₂ and Cu₇S₄/TiO₂, respectively. The results of photoluminescence spectroscopy, transient photocurrent spectra, ultraviolet–visible diffuse reflectance spectra, and electrochemical impedance spectroscopy collectively demonstrate that the enhanced photocatalytic performance of Air-Cu₇S₄/TiO₂ is attributed to the effective separation of charge carriers and widened photoresponse range. The electron paramagnetic resonance and X-ray photoelectron spectroscopy results indicate that the increase of Cu²⁺ in the Cu₇S₄ nanosheet after calcination can promote the charge transfer. This work provides an effective method to improve the electron migration rate and charge separation of TiO₂, which holds great significance for being extended to other material systems and beyond.

The synthesis of Pt-based nanoparticles (NPs) with ultrasmall feature and tailored structure is of great importance for catalysis yet challenging. In this work, we demonstrate a facile top–down strategy for the fabrication of small-sized Pt-based intermetallic compounds (IMCs) with L1₀ structure through the evaporation of Cd under high temperature. Impressively, such thermal treatment can be used as a versatile strategy for creating binary, ternary, quaternary, quinary, and senary L1₀-Pt-based IMCs. Moreover, the small-sized Pt-based IMCs display high stability against high temperature of 700 °C, which can serve as active and selective catalyst for the selective hydrogenation of 4-nitrophenylacetylene. This work may not only provide a versatile top–down strategy for fabricating highly stable small-sized Pt-based NPs with L1₀ structure, but also promote their extensive applications in catalysis and beyond.

Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction (HOR), yet its specific role is largely undecoded. Here, ultrathin Pt nanowires (NWs) are selected as models for revealing the significance of Ni modification on HOR by precisely positioning Ni on distinct positions of Pt NWs. Ni solely influences the electronic properties of Pt and thus weakens ^*H adsorption when it is located in the core of PtNi alloyed NWs, leading to a moderate improvement of alkaline HOR activity. When Ni is distributed in both core and surface of PtNi alloyed NWs, Ni strongly weakens ^*H adsorption but strengthens ^*OH adsorption. On the other hand, the electronic properties of Pt are hardly influenced when Ni is deposited on the surface of Pt NWs, on which the strong ^*H and ^*OH adsorptions lead to the improved HOR activity. This work reveals the significance of Ni modification on HOR, but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.

The design of highly active and stable RuO₂-based nanostructures for acidic oxygen evolution reaction (OER) is extremely important for the development of water electrolysis technology, yet remains great challenges. We here demonstrate that the incorporation of S into RuCuO nanorings (NRs) can significantly enhance the acidic OER performance. Experimental investigations show that the incorporation of S can optimize the interaction of Ru and O, and therefore significantly suppresses the dissolution of Ru in acidic condition. The optimized catalyst (S_H-RuCuO NRs) displays superior OER performance to the commercial RuO₂/C. Impressively, the S_H-RuCuO NRs can exhibit significantly enhanced stability for 3,000 cycles of cyclic voltammetry test and more than 250 h chronopotentiometry test at 10 mA·cm⁻² in 0.5 M H₂SO₄. This work highlights a potential strategy for designing active and stable RuO₂-based electrocatalysts for acidic OER.

Although high-efficiency production of hydrogen peroxide (H₂O₂) can be realized separately by means of direct, electrochemical, and photocatalytic synthesis, developing versatile catalysts is particularly challenging yet desirable. Herein, for the first time we reported that palladium-sulphur nanocrystals (Pd-S NCs) can be adopted as robust and universal catalysts, which can realize the efficient O₂ conversion by three methods. As a result, Pd-S NCs exhibit an excellent selectivity (89.5%) to H₂O₂ with high productivity (133.6 mol·kg_cat⁻¹·h⁻¹) in the direct synthesis, along with the significantly enhanced H₂O₂ production activity and stability via electrocatalytic and photocatalytic syntheses. It is demonstrated that the isolated Pd sites can enhance the adsorption of O₂ and inhibit its O–O bond dissociation, improving H₂O₂ selectivity and reducing H₂O₂ degradation. Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.

Syngas (CO + H₂) is the incredibly important feedstock for producing synthetic fuels and various value-added chemicals. CO₂ electrochemical reduction to syngas is an environmental-friendly and sustainable approach, but still challenging to produce tunable syngas with a wide ratio of CO/H₂. Herein, by modulating the structure and phase, we have successfully obtained a series of copper–indium (Cu-In) catalysts, which are efficient for producing syngas with tunable CO/H₂ ratios. A series of CuIn bimetallic catalysts with different structures from hollow sphere to two-layer hollow sphere and different phases from CuO to Cu₂O are developed. We find that the CO and H₂ are the only gaseous products, in which the CO/H₂ ratios can be readily tuned from 1.2 ± 0.1 to 9.0 ± 1.5 by simply controlling the thermal annealing temperature. It also exhibits high durability during a 10-h test. The unique performance is attributed to the modulated In enrichment on the Cu surfaces during the CO₂ reduction reaction, which causes the differences in binding energies for key reaction intermediates, thus resulting in the tunable composition of syngas. The present work emphasizes a simple yet efficient phase and structure modulating strategy for designing potential electrocatalysts for producing syngas with widely tunable CO/H₂ ratios.