利用低活性载体精确调控活性金属的电子结构是开发高性能电催化剂的有效途径,金属与载体之间高度灵活的电子相互作用可优化催化性能。在此,将Ir纳米团簇(Ir@NC)均匀地负载在氮掺杂炭框架上,制备了一种高效的析氢反应(HER)电催化剂。合...利用低活性载体精确调控活性金属的电子结构是开发高性能电催化剂的有效途径,金属与载体之间高度灵活的电子相互作用可优化催化性能。在此,将Ir纳米团簇(Ir@NC)均匀地负载在氮掺杂炭框架上,制备了一种高效的析氢反应(HER)电催化剂。合成过程是将在900℃下退火制备的沸石咪唑盐框架-8(ZIF-8)作为碳源浸入IrCl_(3)溶液中,然后在400℃的H_(2)/Ar气氛下进行煅烧还原处理。氮掺杂炭框架的三维多孔结构暴露了更多的活性金属位点,Ir簇和氮掺杂炭载体之间的协同效应有效地调节了Ir的电子结构,优化了HER过程。在酸性介质中,Ir@NC表现出显著的HER电催化活性:在10 mA cm^(-2)的条件下,过电位仅为23 mV,具有超低的Tafel斜率(25.8 mV dec^(-1)),且在10 mA cm^(-2)的条件下可稳定运行24 h以上。制备的电催化剂具有高活性、合成路线简便、可规模化制备等优点,有望成为一种极有前途的候选催化剂用于酸性水裂解进行工业制氢。展开更多
商业Pt/C是最常用的析氢催化剂,但其成本高昂,储量有限,因此降低Pt负载量以降低成本是实现长久发展的关键。在Pt中引入其它金属组分对催化剂进行表面修饰等是当下对Pt基纳米催化剂表面改性的研究热点。本论文以酸处理的科琴黑为载体,氯...商业Pt/C是最常用的析氢催化剂,但其成本高昂,储量有限,因此降低Pt负载量以降低成本是实现长久发展的关键。在Pt中引入其它金属组分对催化剂进行表面修饰等是当下对Pt基纳米催化剂表面改性的研究热点。本论文以酸处理的科琴黑为载体,氯亚铂酸钾和硝酸镍为主要金属催化剂前驱体,通过超声辅助还原法将金属离子Pt2+和Ni2+还原为PtNi合金,并以纳米团簇的形式沉积于载体上,成功制备出高效、稳定的酸处理PtNi纳米团簇催化剂(PtNiNC-acid)。研究发现,当电流密度为50 mA cm−2时,PtNiNC-acid的过电位为33 mV;PtNiNC-acid在10 mA cm−2和100 mA cm−2的电流密度下,分别具有55 h和45 h的优良稳定性,这证明了PtNiNC-acid在碱性溶液中具有较高的HER活性和稳定性。Commercial Pt/C is the most commonly used hydrogen evolution catalyst, but its cost is high and its reserves are limited, so reducing Pt load to reduce costs is the key to achieve long-term development. The introduction of other metal components in Pt to modify the surface of the catalyst is the current research focus on the surface modification of Pt based nano-catalyst. In this paper, acid treated Keqin black as the carrier, potassium chlorophosphite and nickel nitrate as the main metal catalyst precursor, the metal ions Pt2+ and Ni2+ were reduced to PtNi alloy by ultrasonic assisted reduction method, and deposited on the carrier in the form of nano-clusters. An efficient and stable acid-treated PtNi nanocluster catalyst (PtNiNC-acid) was successfully prepared. It was found that the overpotential of PtNiNC-acid was 33 mV when the current density was 50 mA cm−2. The excellent stability of PtNiNC-acid at the current densities of 10 mA cm−2 and 100 mA cm−2 for 55 h and 45 h, respectively, proves that PtNiNC-acid has high HER activity and stability in alkaline solutions.展开更多
食品中的重金属污染问题日益严重,对人们的生活产生了严重威胁。文章以2-硫代巴比妥酸(TBA)和甘氨酸(Gly)为配体,制备一种新型的具有红色荧光的铜纳米团簇(CuNCs)。以该团簇作为荧光探针,在基于其优异的选择性及抗其他离子干扰能力的基...食品中的重金属污染问题日益严重,对人们的生活产生了严重威胁。文章以2-硫代巴比妥酸(TBA)和甘氨酸(Gly)为配体,制备一种新型的具有红色荧光的铜纳米团簇(CuNCs)。以该团簇作为荧光探针,在基于其优异的选择性及抗其他离子干扰能力的基础上,对三价铁离子(Fe^(3+))浓度的最低检出线为3.78μmol/L。将加标回收法应用于烧鸡卤水中Fe^(3+)的荧光检测,其加标回收率在93.5%~104.1%之间,相对标准偏差(relative standard deviation,RSD)均低于5.00%,表明该荧光探针对食品中的Fe^(3+)具有良好的检测前景。展开更多
文摘利用低活性载体精确调控活性金属的电子结构是开发高性能电催化剂的有效途径,金属与载体之间高度灵活的电子相互作用可优化催化性能。在此,将Ir纳米团簇(Ir@NC)均匀地负载在氮掺杂炭框架上,制备了一种高效的析氢反应(HER)电催化剂。合成过程是将在900℃下退火制备的沸石咪唑盐框架-8(ZIF-8)作为碳源浸入IrCl_(3)溶液中,然后在400℃的H_(2)/Ar气氛下进行煅烧还原处理。氮掺杂炭框架的三维多孔结构暴露了更多的活性金属位点,Ir簇和氮掺杂炭载体之间的协同效应有效地调节了Ir的电子结构,优化了HER过程。在酸性介质中,Ir@NC表现出显著的HER电催化活性:在10 mA cm^(-2)的条件下,过电位仅为23 mV,具有超低的Tafel斜率(25.8 mV dec^(-1)),且在10 mA cm^(-2)的条件下可稳定运行24 h以上。制备的电催化剂具有高活性、合成路线简便、可规模化制备等优点,有望成为一种极有前途的候选催化剂用于酸性水裂解进行工业制氢。
文摘商业Pt/C是最常用的析氢催化剂,但其成本高昂,储量有限,因此降低Pt负载量以降低成本是实现长久发展的关键。在Pt中引入其它金属组分对催化剂进行表面修饰等是当下对Pt基纳米催化剂表面改性的研究热点。本论文以酸处理的科琴黑为载体,氯亚铂酸钾和硝酸镍为主要金属催化剂前驱体,通过超声辅助还原法将金属离子Pt2+和Ni2+还原为PtNi合金,并以纳米团簇的形式沉积于载体上,成功制备出高效、稳定的酸处理PtNi纳米团簇催化剂(PtNiNC-acid)。研究发现,当电流密度为50 mA cm−2时,PtNiNC-acid的过电位为33 mV;PtNiNC-acid在10 mA cm−2和100 mA cm−2的电流密度下,分别具有55 h和45 h的优良稳定性,这证明了PtNiNC-acid在碱性溶液中具有较高的HER活性和稳定性。Commercial Pt/C is the most commonly used hydrogen evolution catalyst, but its cost is high and its reserves are limited, so reducing Pt load to reduce costs is the key to achieve long-term development. The introduction of other metal components in Pt to modify the surface of the catalyst is the current research focus on the surface modification of Pt based nano-catalyst. In this paper, acid treated Keqin black as the carrier, potassium chlorophosphite and nickel nitrate as the main metal catalyst precursor, the metal ions Pt2+ and Ni2+ were reduced to PtNi alloy by ultrasonic assisted reduction method, and deposited on the carrier in the form of nano-clusters. An efficient and stable acid-treated PtNi nanocluster catalyst (PtNiNC-acid) was successfully prepared. It was found that the overpotential of PtNiNC-acid was 33 mV when the current density was 50 mA cm−2. The excellent stability of PtNiNC-acid at the current densities of 10 mA cm−2 and 100 mA cm−2 for 55 h and 45 h, respectively, proves that PtNiNC-acid has high HER activity and stability in alkaline solutions.
基金This work was supported by the National Natural Science Foundation of China(No.21973022)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012353).
文摘食品中的重金属污染问题日益严重,对人们的生活产生了严重威胁。文章以2-硫代巴比妥酸(TBA)和甘氨酸(Gly)为配体,制备一种新型的具有红色荧光的铜纳米团簇(CuNCs)。以该团簇作为荧光探针,在基于其优异的选择性及抗其他离子干扰能力的基础上,对三价铁离子(Fe^(3+))浓度的最低检出线为3.78μmol/L。将加标回收法应用于烧鸡卤水中Fe^(3+)的荧光检测,其加标回收率在93.5%~104.1%之间,相对标准偏差(relative standard deviation,RSD)均低于5.00%,表明该荧光探针对食品中的Fe^(3+)具有良好的检测前景。
