Pt_(1)/Ni_(6)Co_(1)layered double hydroxides/N-doped graphene for electrochemical non-enzymatic glucose sensing by synergistic enhancement of single atoms and doping

The development of novel single-atom catalysts is important for highly efficient electrochemical catalysis and sensing.In this work,a novel Pt single atoms(SAs)supported on Ni_(6)Co_(1)layered double hydroxides/nitrogen-doped graphene(Pt_(1)/Ni_(6)Co_(1)LDHs/NG)was constructed for electrochemical enzyme-free catalysis and sensing towards glucose.The loading of Pt single atoms increases with doping of Co atoms that generate more anchoring sites for Pt SAs.The resulting Pt_(1)/Ni_(6)Co_(1)LDHs/NG exhibits low oxidative potential of 0.440 V with high sensitivity of 273.78μA·mM^(−1)·cm^(−2)toward glucose,which are 85 mV lower and 15 times higher than those of Ni(OH)_(2),respectively.Pt_(1)/Ni_(6)Co_(1)LDHs/NG also shows excellent selectivity and great stability during 5-week testing.Theoretical and experimental results show that the boosted performance of Pt_(1)/Ni_(6)Co_(1)LDHs/NG originates from its stronger binding energy with glucose and the synergistic effect of Pt SAs,Co doping,and NG.This work provides a general strategy of designing highly active SACs for extending their application in electrochemical sensing.

Enhanced catalytic activity of Ru through N modification toward alkaline hydrogen electrocatalysis

Exploring highly efficient electrocatalysts and understanding the reaction mechanisms for hydrogen electrocatalysis,including hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in alkaline media are conducive to the conversion of hydrogen energy.Herein,we reported a new strategy to boost the HER/HOR performances of ruthenium (Ru) nanoparticles through nitrogen (N) modification.The obtained N-Ru/C exhibit remarkable catalytic performance,with normalized HOR exchange current density and mass activity of 0.56 m A/cm^(2)and 0.54 m A/μg,respectively,about 4 and 4.5 times higher than those of Ru/C,and even twofold enhancement compared to commercial Pt/C.Moreover,at the overpotential of 50 m V,the normalized HER current density of N-Ru/C is 5.5 times higher than that of Ru/C.Experimental and density functional theory (DFT) results verify the electronic regulation of Ru after N incorporation,resulting in the optimized hydrogen adsorption Gibbs free energy (ΔG_(H*)) and hence enhancing the HOR/HER performance.

High-Performance Ru_(2)P Anodic Catalyst for Alkaline Polymer Electrolyte Fuel Cells

Exploring efficient and economical electrocatalysts and understanding the mechanism for alkaline hydrogen oxidation reaction(HOR)are crucial to facilitate the development of alkaline polymer electrolyte fuel cells(APEFCs).Herein,Ru_(2)P was synthesized and used as an anodic HOR electrocatalyst for APEFC,achieving a peak power density of 1.3 W cm^(−2),the highest value among Pt-free anode electrocatalysts reported under the same conditions.Fromthe density functional theory(DFT)calculations and experimental results,it was found that besides the optimized hydrogen binding energy,the enhanced adsorption strength of oxygenated species(OH*)and the reduced work function of Ru_(2)P contributed to the enhanced HOR performance.The normalized exchange current densities of Ru_(2)P/C were 0.37 mA cm_(ECSA)^(−2) and 0.27 mAμgRu^(−1),respectively,both approximately three times higher than those of Ru when conducted in the rotating disk electrode(RDE)system.Our work provides a new pathway for exploring highly active Pt-free HOR electrocatalysts and expanding the family of anodic electrocatalysts for APEFCs.