Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for de...Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for detecting Ni ions.The microfluidic paper-based analytical devices(µPADs)are potential candidates for the detection of water quality parameters including pH,heavy ions,nitrite and so on.However,it suffers from a huge error caused by the environment and artificial mistakes.In this study,we proposed an improved technique route to increase the stability and reliability of microfluidic paper-based analytical devices.The main technique points include a stable light source,a matched camera,improved reliability of the devices,and effective calculated methods.Finally,we established 15 standard curves that could be used to detect nickel ions and obtained uniform colorimetric results with reliability and repeatability.With those improvements,the relative errors for the five types of real water samples from the Zhongshan industrial parks were reduced to 0.26%,14.78%,24.20%,50.29%and 3.53%,respectively.These results were conducive to exploring this technique for the detection of nickel ions in wastewater from the Zhongshan industrial parks.The results demonstrated that the above technique route is promising for the detection of other heavy metal ions in industrial effluent.展开更多
Electrocatalytic ammonia oxidation reaction(AOR)represents a sustainable synthesis approach for valuable nitrogen‑containing compounds like nitrites and nitrates.However,the numerous AOR intermediates often complicate...Electrocatalytic ammonia oxidation reaction(AOR)represents a sustainable synthesis approach for valuable nitrogen‑containing compounds like nitrites and nitrates.However,the numerous AOR intermediates often complicate the precise regulation of target intermediate adsorption,hindering the efficient and selective nitrate/nitrite production.We herein present a NiCu‑BDC MOF with tunable AOR product selectivity,which undergoes a controllable in situ reconstruction into Cu‑β‑NiOOH at 1.7 V vs.RHE,enabling the shift of the reaction pathway from NH_(4)^(+)‑to‑NO_(2)^(−)to NH_(4)^(+)‑to‑NO_(3)^(−).The unique restructuring behavior of this material,combined with its dense active sites,enables highly selective production of nitrites and nitrates(94.9%NO_(2)^(−)selectivity at 1.60 V vs.RHE and 92.6%NO_(3)^(−)selectivity at 1.95 V vs.RHE).Theoretical simulations reveal that the Cu incorporation in NiCu‑BDC modulates the electronic configuration of Ni sites,facilitating moderate adsorption of key NO and NOOH intermediates,thus promoting efficient nitrite generation at low potentials.At higher potentials,NiCu‑BDC undergoes reconstruction to Cu‑β‑NiOOH,stabilizing the conversion of NO_(2)to NO_(2)OH,making nitrate formation thermodynamically favorable and a rapid selectivity shift.This potential‑driven selectivity control not only provides a new strategy for efficient nitrites/nitrates synthesis by simply adjusting applied potentials but also provides fundamental insights into regulating selectivity in multi‑product electrochemical reactions.展开更多
基金funded by the Beijing Natural Science Foundation[Grant No.Z210006]the National Natural Science Foundation of China[Grant No.62275061].
文摘Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for detecting Ni ions.The microfluidic paper-based analytical devices(µPADs)are potential candidates for the detection of water quality parameters including pH,heavy ions,nitrite and so on.However,it suffers from a huge error caused by the environment and artificial mistakes.In this study,we proposed an improved technique route to increase the stability and reliability of microfluidic paper-based analytical devices.The main technique points include a stable light source,a matched camera,improved reliability of the devices,and effective calculated methods.Finally,we established 15 standard curves that could be used to detect nickel ions and obtained uniform colorimetric results with reliability and repeatability.With those improvements,the relative errors for the five types of real water samples from the Zhongshan industrial parks were reduced to 0.26%,14.78%,24.20%,50.29%and 3.53%,respectively.These results were conducive to exploring this technique for the detection of nickel ions in wastewater from the Zhongshan industrial parks.The results demonstrated that the above technique route is promising for the detection of other heavy metal ions in industrial effluent.
基金National Natural Science Foundation of China(No.22379111,22179093,52473287)Key Research Project of Shenzhen(KCXFZ20240903094159005)+1 种基金Fund of the Department of Education of Guangdong Province for Higher Educational Institution(No.2022ZDZX4104,2024KCXTD064)Shenzhen General Project for Institutions of Higher Education(No.20231127113219001).
文摘Electrocatalytic ammonia oxidation reaction(AOR)represents a sustainable synthesis approach for valuable nitrogen‑containing compounds like nitrites and nitrates.However,the numerous AOR intermediates often complicate the precise regulation of target intermediate adsorption,hindering the efficient and selective nitrate/nitrite production.We herein present a NiCu‑BDC MOF with tunable AOR product selectivity,which undergoes a controllable in situ reconstruction into Cu‑β‑NiOOH at 1.7 V vs.RHE,enabling the shift of the reaction pathway from NH_(4)^(+)‑to‑NO_(2)^(−)to NH_(4)^(+)‑to‑NO_(3)^(−).The unique restructuring behavior of this material,combined with its dense active sites,enables highly selective production of nitrites and nitrates(94.9%NO_(2)^(−)selectivity at 1.60 V vs.RHE and 92.6%NO_(3)^(−)selectivity at 1.95 V vs.RHE).Theoretical simulations reveal that the Cu incorporation in NiCu‑BDC modulates the electronic configuration of Ni sites,facilitating moderate adsorption of key NO and NOOH intermediates,thus promoting efficient nitrite generation at low potentials.At higher potentials,NiCu‑BDC undergoes reconstruction to Cu‑β‑NiOOH,stabilizing the conversion of NO_(2)to NO_(2)OH,making nitrate formation thermodynamically favorable and a rapid selectivity shift.This potential‑driven selectivity control not only provides a new strategy for efficient nitrites/nitrates synthesis by simply adjusting applied potentials but also provides fundamental insights into regulating selectivity in multi‑product electrochemical reactions.
