We have sought to improve the electrocatalytic performance of tungsten nitride through synthetic control over chemical composition and morphology.In particular,we have generated a thermodynamically unstable but cataly...We have sought to improve the electrocatalytic performance of tungsten nitride through synthetic control over chemical composition and morphology.In particular,we have generated a thermodynamically unstable but catalytically promising nitrogen-rich phase of tungsten via a hydrothermal generation of a tungsten oxide intermediate and subsequent annealing in ammonia.The net product consisted of three-dimensional(3D)micron-scale flower-like motifs of W2N3;this architecture not only evinced high structural stability but also incorporated the favorable properties of constituent two-dimensional nanosheets.From a performance perspective,as-prepared 3D W2N3 demonstrated promising hydrogen evolution reaction(HER)activities,especially in an acidic environment with a measured overpotential value of−101 mV at a current density of 10 mA/cm^2.To further enhance the electrocatalytic activity,small amounts of precious metal nanoparticles(such as Pt and Au),consisting of variable sizes,were uniformly deposited onto the underlying 3D W2N3 motifs using a facile direct deposition method;these composites were applied towards the CO2 reduction reaction(CO2RR).A highlight of this series of experiments was that Au/W2N3 composites were found to be a much more active HER(as opposed to either a CO2RR or a methanol oxidation reaction(MOR))catalyst.展开更多
基金This material is based on work performed in SSWs laboratory,supported by the U.S.National Science Foundation under Grant No.CHE-1807640.Structural characterization experiments(TEM,SEM,and XPS)for this manuscript were performed in part at the Center for Functional Nanomaterials,located at Brookhaven National Laboratory,which is supported by the U.S.Department of Energy under Contract No.DE-SC-00112704.Authors from Columbia University acknowledge support from the U.S.Department of Energy,Office of Science,Catalysis Science Program(No.DE-FG02-13ER16381).B.M.T.acknowledges support from the U.S.Department of Energy,Office of Science,Office of Workforce Development for Teachers and Scientists,Office of Science Graduate Student Research(SCGSR)program.The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DE-SC0014664.
文摘We have sought to improve the electrocatalytic performance of tungsten nitride through synthetic control over chemical composition and morphology.In particular,we have generated a thermodynamically unstable but catalytically promising nitrogen-rich phase of tungsten via a hydrothermal generation of a tungsten oxide intermediate and subsequent annealing in ammonia.The net product consisted of three-dimensional(3D)micron-scale flower-like motifs of W2N3;this architecture not only evinced high structural stability but also incorporated the favorable properties of constituent two-dimensional nanosheets.From a performance perspective,as-prepared 3D W2N3 demonstrated promising hydrogen evolution reaction(HER)activities,especially in an acidic environment with a measured overpotential value of−101 mV at a current density of 10 mA/cm^2.To further enhance the electrocatalytic activity,small amounts of precious metal nanoparticles(such as Pt and Au),consisting of variable sizes,were uniformly deposited onto the underlying 3D W2N3 motifs using a facile direct deposition method;these composites were applied towards the CO2 reduction reaction(CO2RR).A highlight of this series of experiments was that Au/W2N3 composites were found to be a much more active HER(as opposed to either a CO2RR or a methanol oxidation reaction(MOR))catalyst.
