Recent advances in energy chemistry of precious-metal-free catalysts for oxygen electrocatalysis

The oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) are coupled with various sustainable energy systems and are significant for the future energy scenario. Both of them suffer from sluggish kinetics, which calls for cost-effective and high-performance electrocatalysts to promote. The oxygen electrolysis of OER and ORR is heterogeneous reaction, which involves reactant and electron transfer, and a serial of complicate surface reactions. Both intrinsic catalyst activity and extrinsic physicochemical characters play a vital role in overall electrocatalytic reactivity. Herein. recent advances in rational design and effective construction of precious-metal-free materials are reviewed for OER and ORR, respectively, in the respects of electronic structure regulation, nanostructure tailor, and freestanding electrode fabrication. The reaction mechanism of OER and ORR are also updated. This review provides emerging energy chemistry concepts and materials chemistry strategies of electrocatalysts for OER and ORR, which is also enlightening for other energy conversion devices with targeted optimization.

Advances in the application of nanomaterials for the electrocatalytic detection of drugs of abuse

Drug abuse has proliferated at an unprecedented rate worldwide,posing significant public health challenges that directly impact society,criminality,and the economy.This review presents the application of nanomaterials for qualitative and quantitative electrocatalytic analysis of drugs of abuse,mostly opioids(such as heroin(HER),morphine(MOR),codeine(COD),fentanyl(FEN),and tramadol(TR)),and addictive stimulants(such as cocaine(COC)and methamphetamine(MAM))via direct oxidation.Electroanalytical techniques have attracted attention for generating point-of-use sensors because of their low cost,portability,ease of use,and the possibility of miniaturization.Electroanalytical-based devices can assist first responders with tools to identify unknown powders and to treat victims of drug abuse.Based on the drug therapeutic and usage purposes,research advances in drug electroanalysis can be classified and discussed with special emphasis on the electrochemical reaction mechanism of the drug.Therefore,this review discusses sensor enhancement based on the electrocatalytic properties introduced by various strategies,such as surface nanostructuring,the use of conducting polymers,and anodization of electrode surfaces Finally,a critical outlook is presented with recommendations and prospects for future development.