Micron sized hexagon- and flower-like nanostructures of lead oxide（α-PbO2） have been synthesized by very simple and cost effective route of anodic oxidation of lead sheet. These structures were easily obtained by t...Micron sized hexagon- and flower-like nanostructures of lead oxide（α-PbO2） have been synthesized by very simple and cost effective route of anodic oxidation of lead sheet. These structures were easily obtained by the simple variation of applied voltage from 2-6 V between the electrodes. Lead sheet was used as an anode and platinum sheet served as a cathode. Anodic oxidation at 2 V resulted in the variable edge sized（1-2 μm） hexagon-like structures in the electrolyte. When the applied potential was increased to 4 V a structure of distorted hexagons consisting of some flower-like structures were obtained. Further increment of potential up to 6 V resulted in flower like structures of α-PbO2 having six petals. The diameter of the flower-like structures was 200-500 nm and the size of a petal was 100-200 nm.展开更多
The flower-like silver nanoparticles have been synthesized by reducing silver nitrate （AgNO3） with ascorbic acid （AA） as the reductant and polyvinyl pyrrolidone （PVP） as the capping agent under vigorous stirring...The flower-like silver nanoparticles have been synthesized by reducing silver nitrate （AgNO3） with ascorbic acid （AA） as the reductant and polyvinyl pyrrolidone （PVP） as the capping agent under vigorous stirring. Such flower-like nanoparticles are aggregates of small nanoplates and nanorods. They were tested as substrates for the surface-enhanced Raman scattering （SERS）, showing high sensitivity for detecting Rhodamine 6G （RBG） at a concentration as low as 10 7 mol/L. It has been found that replacing mechanical stirring with ultrasound sonication would drastically change the particle morphology, from flower-like nanoparticles to well-dispersed smaller nanoparticles. Furthermore, when trace amounts of NaC1 were added into the reagents, well-dispersed Ag nanoparticles formed even in vigorous stirring. These phenomena can be explained with the diffusion and reactant supply during nucleation and growth of Ag nanoparticles.展开更多
Designing efficient electrocatalysts for efficient hydrogen evolution is extremely desired but challenging. Herein, we report a facile MOF-assisted strategy to synthesize the hierarchical hollow spherical NiRu-C nanoh...Designing efficient electrocatalysts for efficient hydrogen evolution is extremely desired but challenging. Herein, we report a facile MOF-assisted strategy to synthesize the hierarchical hollow spherical NiRu-C nanohybrid with closely packed rod-like bulges on the surface. Benefited from the more exposed active sites of NiRu-C nanohybrid and the efficient electron/mass transport in its unique hierarchical hollow spherical nanostructure, the optimized nanohybrid showed excellent performance for alkaline hydrogen evolution with ultralow overpotentials, which are much superior to those of Pt/C and the overwhelming majority of reported electrocatalysts. The interpretation of the reaction mechanism was further discussed with DFT calculations. Our research may provide a guidance for the development of advanced electrocatalysts with controlled morphology and excellent performance for future energy applications.展开更多
基金financial support from USACH-Chile, Council of Scientific and Industrial Research (CSIR) and University Grant Commission (UGC) New Delhi, India
文摘Micron sized hexagon- and flower-like nanostructures of lead oxide（α-PbO2） have been synthesized by very simple and cost effective route of anodic oxidation of lead sheet. These structures were easily obtained by the simple variation of applied voltage from 2-6 V between the electrodes. Lead sheet was used as an anode and platinum sheet served as a cathode. Anodic oxidation at 2 V resulted in the variable edge sized（1-2 μm） hexagon-like structures in the electrolyte. When the applied potential was increased to 4 V a structure of distorted hexagons consisting of some flower-like structures were obtained. Further increment of potential up to 6 V resulted in flower like structures of α-PbO2 having six petals. The diameter of the flower-like structures was 200-500 nm and the size of a petal was 100-200 nm.
基金financial support for this work from the Natural Science Foundation for Young Scientists of Shanxi Province of China (No. 2015021078)International Cooperation of Science and Technology Project in Shanxi Province of China (No. 2014081006-2)
文摘The flower-like silver nanoparticles have been synthesized by reducing silver nitrate （AgNO3） with ascorbic acid （AA） as the reductant and polyvinyl pyrrolidone （PVP） as the capping agent under vigorous stirring. Such flower-like nanoparticles are aggregates of small nanoplates and nanorods. They were tested as substrates for the surface-enhanced Raman scattering （SERS）, showing high sensitivity for detecting Rhodamine 6G （RBG） at a concentration as low as 10 7 mol/L. It has been found that replacing mechanical stirring with ultrasound sonication would drastically change the particle morphology, from flower-like nanoparticles to well-dispersed smaller nanoparticles. Furthermore, when trace amounts of NaC1 were added into the reagents, well-dispersed Ag nanoparticles formed even in vigorous stirring. These phenomena can be explained with the diffusion and reactant supply during nucleation and growth of Ag nanoparticles.
基金supported by the One Thousand Young Talents Program under the Recruitment Program of Global Expertsthe National Natural Science Foundation of China(NSFC)(21901246 and 21905279)the Natural Science Foundation of Fujian Province(2020J01116 and 2019J05158)。
文摘Designing efficient electrocatalysts for efficient hydrogen evolution is extremely desired but challenging. Herein, we report a facile MOF-assisted strategy to synthesize the hierarchical hollow spherical NiRu-C nanohybrid with closely packed rod-like bulges on the surface. Benefited from the more exposed active sites of NiRu-C nanohybrid and the efficient electron/mass transport in its unique hierarchical hollow spherical nanostructure, the optimized nanohybrid showed excellent performance for alkaline hydrogen evolution with ultralow overpotentials, which are much superior to those of Pt/C and the overwhelming majority of reported electrocatalysts. The interpretation of the reaction mechanism was further discussed with DFT calculations. Our research may provide a guidance for the development of advanced electrocatalysts with controlled morphology and excellent performance for future energy applications.
