Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the ...Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the most conventional and classical non-noble metal-based electrocatalysts for OER,while TM basic salts[M^(2+)(OH)_(2-x)(A_(m^(-))_(x/m),A=CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)]consisting of OH−and another anion have drawn extensive research interest due to its higher catalytic activity in the past decade.In this review,we summarize the recent advances of TM basic salts and their application in OER and further overall water splitting.We categorize TM basic salt-based OER pre-catalysts into four types(CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)according to the anion,which is a key factor for their outstanding performance towards OER.We highlight experimental and theoretical methods for understanding the structure evolution during OER and the effect of anion on catalytic performance.To develop bifunctional TM basic salts as catalyst for the practical electrolysis application,we also review the present strategies for enhancing its hydrogen evolution reaction activity and thereby improving its overall water splitting performance.Finally,we conclude this review with a summary and perspective about the remaining challenges and future opportunities of TM basic salts as catalysts for water electrolysis.展开更多
Benefiting from the inherent superiorities in flexibility and mobility,the use of unmanned aerial vehicles(UAVs)as flying base stations for wireless coverage has been of significant interest,especially for rescue serv...Benefiting from the inherent superiorities in flexibility and mobility,the use of unmanned aerial vehicles(UAVs)as flying base stations for wireless coverage has been of significant interest,especially for rescue services.This work concerns the reliable emergency communication based on commercial micro-sized UAVs due to their high availability and low cost.To decrease the weight overloads and to improve the power efficiency,a UAV body conformal and omnidirectional antenna is first presented based on the characteristic mode analysis.To extend the wireless coverage and to improve the communication quality of the UAV network,a UAV flight formation is then proposed and analyzed.In addition,the propagation analyses for the proposed UAV transmitter designs are performed in a realistic hilly canyon region.Simulations and comparisons are presented to demonstrate the effectiveness of the proposed designs in emergency communications and performance enhancement through the UAV flight formation.展开更多
基金supported by the financial support from Natural Science Foundation of China(Nos.21871065,22209129 and 22071038)High-Level Innovation and Entrepreneurship(QCYRCXM-2022-123)+1 种基金support from the“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J024)“Young Talent Lift Plan”of Xi’an city(095920221352).
文摘Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the most conventional and classical non-noble metal-based electrocatalysts for OER,while TM basic salts[M^(2+)(OH)_(2-x)(A_(m^(-))_(x/m),A=CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)]consisting of OH−and another anion have drawn extensive research interest due to its higher catalytic activity in the past decade.In this review,we summarize the recent advances of TM basic salts and their application in OER and further overall water splitting.We categorize TM basic salt-based OER pre-catalysts into four types(CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)according to the anion,which is a key factor for their outstanding performance towards OER.We highlight experimental and theoretical methods for understanding the structure evolution during OER and the effect of anion on catalytic performance.To develop bifunctional TM basic salts as catalyst for the practical electrolysis application,we also review the present strategies for enhancing its hydrogen evolution reaction activity and thereby improving its overall water splitting performance.Finally,we conclude this review with a summary and perspective about the remaining challenges and future opportunities of TM basic salts as catalysts for water electrolysis.
基金This work was supported in part by National Natural Science Foundation of China(NSFC)under Grant No.61901020the Open Research Fund from Shenzhen Research Institute of Big Data under Grant No.2019ORF01012.
文摘Benefiting from the inherent superiorities in flexibility and mobility,the use of unmanned aerial vehicles(UAVs)as flying base stations for wireless coverage has been of significant interest,especially for rescue services.This work concerns the reliable emergency communication based on commercial micro-sized UAVs due to their high availability and low cost.To decrease the weight overloads and to improve the power efficiency,a UAV body conformal and omnidirectional antenna is first presented based on the characteristic mode analysis.To extend the wireless coverage and to improve the communication quality of the UAV network,a UAV flight formation is then proposed and analyzed.In addition,the propagation analyses for the proposed UAV transmitter designs are performed in a realistic hilly canyon region.Simulations and comparisons are presented to demonstrate the effectiveness of the proposed designs in emergency communications and performance enhancement through the UAV flight formation.
