Rationally manipulating the in‐situ formed catalytically active surface of catalysts remains a great challenge for a highly efficient water electrolysis.Here,we report a cationic oxidation method which can adjust the...Rationally manipulating the in‐situ formed catalytically active surface of catalysts remains a great challenge for a highly efficient water electrolysis.Here,we report a cationic oxidation method which can adjust the leaching of the in‐situ catalyst and promote the reconstruction of dynamic surface for the oxygen evolution reaction(OER).The chlorine doping can reduce the possibility of triggering in‐situ cobalt oxidation and chlorine leaching,leading to a transformation of the surface chlorine doped LaCoO_(3)(Cl‐LaCoO_(3))into an intricate amorphous(oxygen)hydroxide phase.And thus,Cl‐LaCoO_(3)nanocrystals shows an ultralow overpotential of 342 mV at the current density of 10 mA cm^(–2)and Tafel slope of 76.2 mV dec–1.Surface reconstructed Cl‐LaCoO_(3)is better than many of the most advanced OER catalysts and has proven significant stability.This work provides a new prospect for designing a high‐efficiency electrocatalyst with optimized perovskite‐structure in renewable energy system.展开更多
Constructing efficient carbon material with enhanced mass transfer ability from vacuum residuum(VR)is of prime industrial and scientific significance.Herein,we demonstrated a one-pot synthesis of metal-free and highly...Constructing efficient carbon material with enhanced mass transfer ability from vacuum residuum(VR)is of prime industrial and scientific significance.Herein,we demonstrated a one-pot synthesis of metal-free and highly symmetric hollow carbon cubes(HCCs)using cost-efficient vacuum residuum(VR)as a C/N/S source.By multi-techniques such as TEM,SEM,Raman,XPS,and XRD,it is found that the CTAB surfactant plays an important role in emulsifying and forming oil-in-water suspension particles.Subsequently,high aromatics contents in VR favor the formation of HCCs shell by graphitization on the surface of Na Cl template.Notably,heavy metals(e.g.,V,Ni)are not enriched in carbon skeleton due to the unique graphitization mechanism.This metal-free HCCs catalyst showed good catalytic stability and high selectivity towards direct and local electrochemical production of hydrogen peroxide(H_(2)O_(2))through two-electron O_(2)reduction due to enhanced mass transfer ability.The results provide a novel avenue to synthesize metal-free cubic carbon material from low-cost and plentiful VR,which are essential to the design of more efficient catalysts for O_(2)reduction to H_(2)O_(2).展开更多
文摘Rationally manipulating the in‐situ formed catalytically active surface of catalysts remains a great challenge for a highly efficient water electrolysis.Here,we report a cationic oxidation method which can adjust the leaching of the in‐situ catalyst and promote the reconstruction of dynamic surface for the oxygen evolution reaction(OER).The chlorine doping can reduce the possibility of triggering in‐situ cobalt oxidation and chlorine leaching,leading to a transformation of the surface chlorine doped LaCoO_(3)(Cl‐LaCoO_(3))into an intricate amorphous(oxygen)hydroxide phase.And thus,Cl‐LaCoO_(3)nanocrystals shows an ultralow overpotential of 342 mV at the current density of 10 mA cm^(–2)and Tafel slope of 76.2 mV dec–1.Surface reconstructed Cl‐LaCoO_(3)is better than many of the most advanced OER catalysts and has proven significant stability.This work provides a new prospect for designing a high‐efficiency electrocatalyst with optimized perovskite‐structure in renewable energy system.
基金supported by the National Natural Science Foundation of China (21978325)。
文摘Constructing efficient carbon material with enhanced mass transfer ability from vacuum residuum(VR)is of prime industrial and scientific significance.Herein,we demonstrated a one-pot synthesis of metal-free and highly symmetric hollow carbon cubes(HCCs)using cost-efficient vacuum residuum(VR)as a C/N/S source.By multi-techniques such as TEM,SEM,Raman,XPS,and XRD,it is found that the CTAB surfactant plays an important role in emulsifying and forming oil-in-water suspension particles.Subsequently,high aromatics contents in VR favor the formation of HCCs shell by graphitization on the surface of Na Cl template.Notably,heavy metals(e.g.,V,Ni)are not enriched in carbon skeleton due to the unique graphitization mechanism.This metal-free HCCs catalyst showed good catalytic stability and high selectivity towards direct and local electrochemical production of hydrogen peroxide(H_(2)O_(2))through two-electron O_(2)reduction due to enhanced mass transfer ability.The results provide a novel avenue to synthesize metal-free cubic carbon material from low-cost and plentiful VR,which are essential to the design of more efficient catalysts for O_(2)reduction to H_(2)O_(2).
