Institutional Repository of Dalian Institute of Chemical Physics, CAS
Not a member yet
45557 research outputs found
Sort by
PTB7:PC61BM Bulk Heterojunction-Based Photocathodes for Efficient Hydrogen Production in Aqueous Solution
No full textBecause of excellent light absorption and charge separation properties, a polymer bulk heterojunction (BHJ) composed of electron-donor and electron-acceptor is very promising to be used for photoelectrode preparation. In this work, a PTB7:PC61BM BHJ-based photocathode is fabricated for photoelectrochemical (PEC) hydrogen evolution reaction (HER) in aqueous solution. With CuOx and TiOx thin films as interfacial modification layers, the photocathode with full structure (fluorine-doped tin oxide/CuOx/PTB7:PC61BM/TiOx/Pt) generates a maximum photocurrent density up to -7.27 mA cm(-2) and an onset potential as positive as 0.63 V. The half-cell solar-to-hydrogen efficiency is up to 1.5%, outperforming all of the previous BHJ-based photocathodes for HER CuOx is identified to play a role of facilitating charge separation, whereas TiOx improves the charge injection as well as blocks the back migration of holes during the PEC process. The factors including permeation of water and oxygen molecules, incident light spectrum, and current flowing that affect the PEC stability are investigated and discussed
A new NMR crystallographic approach to reveal the calcium local structure of atorvastatin calcium
No full textWe combine experimental and computational determination of Ca-43 solid-state NMR parameters (chemical shift tensors, quadrupolar coupling tensors, and Euler angles) to constrain the structure of the local calcium-ligand coordination environment. A new Ca-43 NMR crystallographic approach which includes an extensive survey of the Cambridge Structural Database and a new symmetry benchmark is developed to enhance the selectivity of structural screening. The application of this method to quadrupolar NMR crystallographic investigations is demonstrated by unearthing the calcium local structure of the active pharmaceutical ingredient atorvastatin calcium trihydrate, the active ingredient in Lipitors, in the absence of diffraction data. This method has been tested by applying it to calcium acetate monohydrate which has a known structure
Photoelectrochemical CO2 reduction to adjustable syngas on grain-boundary-mediated a-Si/TiO2/Au photocathodes with low onset potentials
No full textA photoelectrochemical (PEC) CO2 reduction reaction (CRR) in an aqueous medium is among the most promising methods to produce renewable fuels with the sun and water as the energy and electron source. But a high negative bias remains a prerequisite to achieve an appreciable conversion at present due to the large overpotential of CO2 reduction. This communication describes a PEC CRR with low onset potential on an amorphous silicon (a-Si) photocathode decorated with grain-boundary-rich gold catalysts. Syngas, with high throughput and desirable CO/H2 ratios such as 1 : 2 and 1 : 1, was produced in a wide PEC range from the equilibrium potential E-0(CO2/CO) of -0.1 V vs. the reversible hydrogen electrode (V-RHE) to as positive as 0.4 V-RHE, leading to a half-cell conversion efficiency of 0.42%. This performance represents the highest half-cell efficiency and lowest onset potential for CO2 reduction ever reported among aqueous PEC cathodes under 1 sun illumination. The a-Si/TiO2/Au photocathodes exhibit excellent stability in a wide potential range, with a high CO mass activity up to 180 ampere per gram of gold at -0.1 V-RHE. Controlling the grain boundary provides powerful potential to adjust the product selectivity in PEC CO2 reduction
