Combining the core-shell structure with the optimization of surface composition and structure in the shell is a fantastic strategy to enhance the electrocatalytic performances. Here, we synthesized trimetallic Au@PtxSny core-shell nanoparticles (NPs) with tunable composition and structure of Pt-Sn alloyed shells. Impressively, the Au@PtSn core-shell NPs with hexagonal PtSn alloyed shells exhibited the highest mass activity and specific activity toward ethanol oxidation reaction (EOR) in alkaline electrolyte, which are 13.0 and 12.7 times higher than those of the commercial Pt/C. In addition, the Au@PtSn core-shell NPs displayed the best stability compared to commercial Pt/C, with only 44.8% loss vs. 86.8% loss in mass activity after 1,000 s due to the stronger anti-poisoning ability for reaction intermediates. The theory calculations reveal that the introduction of Au core and alloying Pt with Sn both endow Pt with an appropriate d-band center, and thus effectively boosting the EOR activity.
Cobalt-phosphorous (Co P) coatings are promising alternatives for hard chromium due to their outstanding corrosion protection . An excellent Co P coating can efficiently reduce the effects of a corrosive environment. Herein, Co P coatings with a tunable P content, ranging from 5.1 at.% to 20 at.%, are fabricated via a simple electrochemical deposition approach from choline chloride-ethylene glycol (Ethaline)-based deep eutectic solvent (DES) with saccharin (SA) as an additive. The rational introduction of SA induced the formation of close-growing Co P coatings rich in P on the substrate with reduced grain size and surface roughness . It turned out that the crystal structure of the deposited Co P coatings changed from a crystallized state to an amorphous state upon the addition of SA, which accelerated the nucleation rate of the nanocrystals and modified the nucleation model from progressive to instantaneous. The optimal Co P coating prepared exhibited excellent anti-corrosion and barrier protection properties for mild steel in corrosive NaCl solution, functioning up to 10 times better than its counterparts. Our work reveals the central role of additives in tailoring the structure and composition of the deposited Co P coatings in Ethaline-based DES and offers a new avenue for fabricating high-performance coating materials for anti-corrosion applications.
危险品化学品经营许可证（带存储）