The rational fabrication of Pt‐free catalysts for driving the development of practical applications in alkaline water electrolysis and fuel cells is promising but challenging. Herein, a promising approach is outlined for the rational design of multimetallic catalysts comprising multiple active sites including Pd nanoclusters and Ru single atoms anchored at the defective sites of Ni(OH)2 to simultaneously enhance hydrogen evolution reactions (HER) and ethanol oxidation reactions (EOR). Remarkably, Pd12Ru3/Ni(OH)2/C exhibits a remarkably reduced HER overpotential (16.1 mV@10 mA cm−2 with a Tafel slope of 21.8 mV dec−1) as compared to commercial 20 wt.% Pt/C (26.0 mV@10 mA cm−2, 32.5 mV dec−1). More importantly, Pd12Ru3/Ni(OH)2/C possesses a self‐optimized overpotential to 12.5 mV@10 mA cm−2 after 20 000 cycles stability test while a significantly decreased performance for commercial 20wt.% Pt/C (64.5 mV@10 mA cm−2 after 5000 cycles). The mass activity of Pd12Ru3/Ni(OH)2/C for the EOR is up to 3.724 A mgPdRu−1, ≈20 times higher than that of commercial Pd/C. Electrochemical in situ Fourier transform infrared measurements confirm the enhanced CO2 selectivity of Pd12Ru3/Ni(OH)2/C while synergistic and electronic effects of adjacent Ru, Pd, and OHad adsorption on Ni(OH)2 at low potential play a key role during EOR.

Hydroxide-supported atomic structures, particularly single atoms, offer a wide scope for active microenvironmental tuning to enhance catalytic performance, but little has been explored on the electronic synergy between mono- and...

Modulating the dynamic change of catalysts is significant for understanding the mechanism and exploiting better electrocatalysts but remains challenging in oxygen evolution reaction (OER). Herein, ceria-promoted reconstruction of Ni-X (X = S, P, and O) is investigated to unravel the correlation between the reconstructed surface and the OER performance, which further guides the design of prominent electrocatalysts. Interfacial CeO 2 promotes the in situ reconfiguration of Ni-X via strengthening hydroxyl adsorption, generating highly active CeO 2 -NiOOH interfaces. Moreover, rich oxygen vacancies formed after breaking Ni-S/P bonds and leaching S/P anions render Ni 3 S 2 and Ni 2 P superior to NiO with the same CeO 2 modification, highlighting another dependence on pre-catalyst materials chemistry. Theoretical analysis further confirms that the co-presence of CeO 2 -NiOOH interfaces and oxygen vacancies can harmoniously regulate intermediate chemisorption toward favorable OER kinetics. As a proof of concept, CeO 2 -modified Ni 3 S 2 exhibits low overpotentials of 251 and 364 mV at the current densities of 10 and 100 mA cm −2 in 1.0 M KOH, respectively, performing among the best of recently reported Ni-based counterparts.

No abstract

Lately, the color-changeable electrochromic technology has been applied onto mobile phones to shield the cameras, where special demands for the electrochromic working unit are a fast bleaching response time, a high transmittance in the bleached state when cameras work, a long-lasting memory effect in the colored state when cameras are in the standby mode, and excellent cyclic stability and safety. However, in electrochromic films, long-lasting memory effect always means a slow response time. And a traditional electrochromic device contains at least five functional layers, which limits its transmittance in the bleached state on a large scale. Herein, we designed a three-layered all-solid-state camera shielding device (ITO/WO3/electrolyte) with necessary WO3 electrochromic working units and a lateral WO3 storage unit which is known as the shoulder-by-shoulder electrochromic structure. Owing to the high-performance WO3 film and the special characteristics of the shoulder-by-shoulder electrochromic technology, our greatly simplified device perfectly met all the above-mentioned requirements. This research will be a strong push for the applications of electrochromic technology onto all kinds of mobile devices.