Water splitting powered by clean electricity is a sustainable and promising approach to produce green hydrogen.Currently,noble metal(e.g.Iridium,Ruthenium,Platinum)-based catalysts are most widely used for water split...Water splitting powered by clean electricity is a sustainable and promising approach to produce green hydrogen.Currently,noble metal(e.g.Iridium,Ruthenium,Platinum)-based catalysts are most widely used for water splitting electrolysis.However,noble metal-based catalysts often suffer from multiple disadvantages,including high cost,low selectivity and poor durability.The emergence of metal-organic framework nanosheets(MOFNSs)attracts significant attention due to their unique advantages.Here,a concise,yet comprehensive and critical,review of recent advances in the field of MOFNSs is provided.This review explains the fundamental oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)catalytic mechanisms as well as key characterization techniques for the structure-activity relationship study are discussed.Moreover,it discusses efficient design strategies and the brief research advances of MOFNSs in HER,OER,and bifunctional electrocatalysis,along with some challenges and opportunities.展开更多
The hydrogen evolution reaction(HER)as a fundamental process in electrocatalysis plays a significant role in clean energy technologies.For an energy-efficient HER,it demands an effective,durable,and low-cost catalyst ...The hydrogen evolution reaction(HER)as a fundamental process in electrocatalysis plays a significant role in clean energy technologies.For an energy-efficient HER,it demands an effective,durable,and low-cost catalyst to trigger proton reduction with minimal overpotential and fast kinetics.Here,we successfully fabricate a highly efficient HER catalyst of N-C/Co/Mo_(2)C holey nanorods with Co/b-Mo_(2)C nanoparticles uniformly embedded in nitrogen-doped carbon(N-C/Co/Mo_(2)C)by pyrolyzing the molybdate-coordinated zeolitic imidazolate framework(ZIF-67/MoO_(4)^(2-))holey nanorods,which result from the reaction between CoMoO_(4)and Me IM in a methanol/water/triethylamine mixed solution.The uniform distribution of MoO_(4)^(2-)in the ZIF-67/MoO_(4)^(2-)enables Co/β-Mo_(2)C nanoparticles to be welldistributed within nitrogen-doped carbon holey nanorods.This synthetic strategy endows the N-C/Co/Mo_(2)C catalyst with uniformly decorated bimetal,thus attaining excellent HER electrocatalytic activities with a small overpotential of 142.0 m V at 10 m A cm^(-2)and superior stability in 1.0 mol L^(-1)KOH aqueous solution.展开更多
This research addresses the new level-direction decomposition in the area of image watermarking as the further development of investigations. The main process of realizing a watermarking framework is to generate a wat...This research addresses the new level-direction decomposition in the area of image watermarking as the further development of investigations. The main process of realizing a watermarking framework is to generate a watermarked image with a focus on contourlet embedding representation. The approach performance is evaluated through several indices including the peak signal-to-noise ratio and structural similarity, whereby a set of attacks are carried out using a module of simulated attacks. The obtained information is analyzed through a set of images, using different color models, to enable the calculation of normal correlation. The module of the inverse of contourlet embedding representation is correspondingly employed to obtain the present watermarked image, as long as a number of original images are applied to a scrambling module, to represent the information in disorder. This allows us to evaluate the performance of the proposed approach by analyzing a complicated system, where a decision making system is designed to find the best level and the corresponding direction regarding contourlet embedding representation. The results are illustrated in appropriate level-direction decomposition. The key contribution lies in using a new integration of a set of subsystems, employed based upon the novel mechanism in contourlet embedding representation, in association with the decision making system. The presented approach is efficient compared with state-of-the-art approaches, under a number of serious attacks. A number of benchmarks are obtained and considered along with the proposed framework outcomes. The results support our ideas.展开更多
文摘Water splitting powered by clean electricity is a sustainable and promising approach to produce green hydrogen.Currently,noble metal(e.g.Iridium,Ruthenium,Platinum)-based catalysts are most widely used for water splitting electrolysis.However,noble metal-based catalysts often suffer from multiple disadvantages,including high cost,low selectivity and poor durability.The emergence of metal-organic framework nanosheets(MOFNSs)attracts significant attention due to their unique advantages.Here,a concise,yet comprehensive and critical,review of recent advances in the field of MOFNSs is provided.This review explains the fundamental oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)catalytic mechanisms as well as key characterization techniques for the structure-activity relationship study are discussed.Moreover,it discusses efficient design strategies and the brief research advances of MOFNSs in HER,OER,and bifunctional electrocatalysis,along with some challenges and opportunities.
基金National Institute of Advanced Industrial Science and Technology(AIST)the Japan Society for the Promotion of Science(JSPS)for financial support。
文摘The hydrogen evolution reaction(HER)as a fundamental process in electrocatalysis plays a significant role in clean energy technologies.For an energy-efficient HER,it demands an effective,durable,and low-cost catalyst to trigger proton reduction with minimal overpotential and fast kinetics.Here,we successfully fabricate a highly efficient HER catalyst of N-C/Co/Mo_(2)C holey nanorods with Co/b-Mo_(2)C nanoparticles uniformly embedded in nitrogen-doped carbon(N-C/Co/Mo_(2)C)by pyrolyzing the molybdate-coordinated zeolitic imidazolate framework(ZIF-67/MoO_(4)^(2-))holey nanorods,which result from the reaction between CoMoO_(4)and Me IM in a methanol/water/triethylamine mixed solution.The uniform distribution of MoO_(4)^(2-)in the ZIF-67/MoO_(4)^(2-)enables Co/β-Mo_(2)C nanoparticles to be welldistributed within nitrogen-doped carbon holey nanorods.This synthetic strategy endows the N-C/Co/Mo_(2)C catalyst with uniformly decorated bimetal,thus attaining excellent HER electrocatalytic activities with a small overpotential of 142.0 m V at 10 m A cm^(-2)and superior stability in 1.0 mol L^(-1)KOH aqueous solution.
文摘This research addresses the new level-direction decomposition in the area of image watermarking as the further development of investigations. The main process of realizing a watermarking framework is to generate a watermarked image with a focus on contourlet embedding representation. The approach performance is evaluated through several indices including the peak signal-to-noise ratio and structural similarity, whereby a set of attacks are carried out using a module of simulated attacks. The obtained information is analyzed through a set of images, using different color models, to enable the calculation of normal correlation. The module of the inverse of contourlet embedding representation is correspondingly employed to obtain the present watermarked image, as long as a number of original images are applied to a scrambling module, to represent the information in disorder. This allows us to evaluate the performance of the proposed approach by analyzing a complicated system, where a decision making system is designed to find the best level and the corresponding direction regarding contourlet embedding representation. The results are illustrated in appropriate level-direction decomposition. The key contribution lies in using a new integration of a set of subsystems, employed based upon the novel mechanism in contourlet embedding representation, in association with the decision making system. The presented approach is efficient compared with state-of-the-art approaches, under a number of serious attacks. A number of benchmarks are obtained and considered along with the proposed framework outcomes. The results support our ideas.
