Qingyang Li

An array catalyst is promising to lead the way for future developments of high-performance catalysts, owing to its large specific surface area, excellent activity, stability, and reusability. Herein, a series of new candidates, i.e., the transition-metal nanoparticles supported on zinc oxide nanowires (TM/ZnO), are introduced into this catalytic system. The free-standing TM/ZnO nanoarray catalysts can be controllably constructed on the conductive substrate through a flexible, economical, and scalable approach combining electrodeposition and hydrothermal reaction and exhibit very high photocatalytic activity toward the reduction reaction of nitrate to ammonia. The results demonstrate that the catalytic activity of TM/ZnO primarily originates from iron (Fe), cobalt (Co), nickel (Ni), or copper (Cu) nanoparticles, rather than the ZnO nanoarray and stainless steel substrate. When the structure and composition are very close, the photocatalytic activity of Co/ZnO for the nitrate reduction reaction is significantly superior to those of Cu/ZnO, Ni/ZnO, and Fe/ZnO, possibly owing to its smaller charge-transfer resistance and bigger photocurrent. This universal synthetic methodology paves a novel avenue for developing other ZnO nanoarray-supported metal catalysts, showing great prospects in environmental and energy-related applications.

A novel free‐standing high‐entropy oxides (HEOs) catalyst, i.e., zinc oxide nano‐array decorated with iron, cobalt, nickel, copper, and zinc oxides (ZnO‐HEOs), is proposed firstly. It exhibits outstanding electrocatalytic nitrate reduction reaction (NO ₃ ⁻ RR) capacity in the neutral electrolyte, achieving a Faradaic efficiency of ∼99.42% with an ammonia yield of ∼34.09 mg cm ⁻² h ⁻¹ in a membrane electrode assembly under optimal conditions. Meanwhile, it delivers an open‐circuit potential of ∼1.55 V with a peak power density of ∼5.33 mW cm ⁻² in a zinc‐nitrate battery. The performance of ZnO‐HEOs surpasses that of HEOs powder counterparts and most previously reported catalysts or cathode materials, because the difference in electron work function between ZnO and HEOs triggers their interfacial synergistic effect. It facilitates the charge transfer from ZnO‐HEOs to key intermediates, thereby changing the rate‐determining step of ZnO and HEOs toward the electrocatalytic NO ₃ ⁻ RR, and decreasing their energy barrier simultaneously. More importantly, the ZnO‐HEOs can also sustain exceptional stability in both electrochemical systems, due to the fact that the ZnO supports effectively stabilize the active sites of HEOs. This work not only offers a route for the rational design of efficient and stable self‐supporting HEOs, but also promotes their practical applications in energy‐ and environment‐related fields.

The study aimed to examine the effect of centrifugation time and speed on the accuracy, surface characteristics, and mechanical properties of temporary crowns printed using digital light processing (DLP). Experimental groups were centrifuged at different durations (1 and 5 min) and speeds (100, 500, and 2500 rpm), whereas the control group underwent ultrasonic cleaning with isopropanol for 5 min. Evaluation parameters included three-dimensional accuracy (trueness and precision) of the inner and margin surfaces. Surface morphology was examined using scanning electron microscopy, and roughness parameters (Sa, Sq, Sz) were quantified. Mechanical properties, including flexural strength (FS), flexural modulus, and fracture load, were evaluated using a three-point bending test. Inner surface accuracy increased with increased centrifugation time and speed (P < 0.05). Margin surface accuracy was influenced by centrifugation speed (P < 0.05) but not by time (P > 0.05). Accuracy in the 500 rpm/5-min group was comparable to the control group (P > 0.05). Surface roughness decreased with increasing centrifugation intensity; Group F (2500 rpm for 5 min) showed lower Sa (0.287 ± 0.137 μm) and Sq (0.739 ± 0.449 μm) values. FS increased with increasing time and speed, with Group F (158.5 ± 18.73 MPa) exceeding the control group (119.8 ± 11.04 MPa; P = 0.0009). Centrifugation time and speed significantly influenced dimensional accuracy, surface characteristics, and mechanical properties of DLP-manufactured temporary crowns. The 5-min/500 rpm and 5-min/2500 rpm conditions yielded the highest trueness and precision, whereas 2500 rpm for 5 min produced optimal surface quality and strength..

Synthetic ammonia is of great significance to the development of industry and agriculture. At present, its manufacturing production is still dominated by century‐old Haber–Bosch process, involving in huge amounts of energy consumptions and carbon dioxide emissions. Hence, it is of great significance to develop green and sustainable alternative technologies, such as photo‐, thermo‐, and electro‐catalytic syntheses of ammonia. Nevertheless, the intrinsic inertness of nitrogen results in low ammonia yield of above candidates, which still cannot meet commercialization expectations. Recent researches have successfully demonstrated that plasma can effectively activate the decomposition of nitrogen and hydrogen under ambient conditions, thereby significantly improving the ammonia yield of these alternative strategies. This review systematically summarizes the classification and reaction mechanism of plasma for this reason, and discusses the synergy between different plasma and catalytic methods along with energy consumptions in detail. In the meantime, the future development trend is also forecasted.

The sluggish kinetics of oxygen evolution reaction (OER) poses a great challenge to the industrial promotion of electrocatalytic water splitting and zinc-air battery. Herein, we demonstrate that the kinetic limitation of the OER imposed by a conventional adsorbate evolution mechanism can be successfully overcome through activating lattice oxygen in the electrocatalyst. For example, incorporating aluminum (Al) into high-entropy oxides (HEO) remarkably enhances the oxygen vacancy concentration, facilitates the generation of reactive oxygen species, and promotes the deprotonation during the electrochemical OER process, thereby boosting the kinetic reaction. This defect engineering strategy effectively decreases the energy barrier associated with the lattice oxygen oxidation and optimizes the configurational entropy of HEO, resulting in remarkable structural stability. Consequently, the developed HEO decorated with Al (HEO-Al) achieves an overpotential of ∼206 mV at 10 mA cm^-2 in water electrolysis and a power density (∼20 mW cm^-2) in rechargeable zinc-air battery, with long-term stability of 100 h, realizing an optimal balance between electrocatalytic activity and stability. More importantly, the performances of HEO-Al are significantly superior to those of the HEO counterpart (∼260 mV, ∼1.5 mW cm^-2) and commercial ruthenium oxide (∼359 mV, ∼5 mW cm^-2), showing great competitiveness and application prospect. These results offer essential inspiration for other electrochemical applications dominated by the OER at the same time.