碳点(CDs)因其较大的比表面积和较快的电子转移特性,已成为能量转换应用领域一种新兴的纳米炭材料。本文以低成本的石油焦为原料,通过简便的一步电化学刻蚀方法制备了硼氮双掺杂碳点(BN-CDs)。与单掺杂碳点B-CDs和N-CDs相比,双掺杂BN-CD...碳点(CDs)因其较大的比表面积和较快的电子转移特性,已成为能量转换应用领域一种新兴的纳米炭材料。本文以低成本的石油焦为原料,通过简便的一步电化学刻蚀方法制备了硼氮双掺杂碳点(BN-CDs)。与单掺杂碳点B-CDs和N-CDs相比,双掺杂BN-CDs表现出更优异的四电子氧还原电催化活性,具有更正的起始电位(Eonset=0.958 V)和大的扩散极限电流密度(j D=-4.32 mA cm~(-2)),且长期稳定性和甲醇耐受性优于商用Pt/C催化剂。密度泛函理论计算(DFT)研究表明,B、N双掺杂的协同效应促进了O_2分子的吸附,有助于提高碳点的电催化活性。本研究为纳米炭材料的设计及其在能量转换领域的应用提供了新的思路。展开更多
To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozone...To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013.The results showed that the mean background current and its standard deviation were 0.03(0.04)μA and 0.02(0.03)μA in Beijing(Changchun).The average response time and its standard deviation were 27.8 s(30.4 s)and 4.0 s(3.7 s)in Beijing(Changchun).The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer.Large variation in ozone partial pressure was observed at the middle levels of the atmosphere(10–17 km).A more marked gradient of ozone change was observed in Beijing(3.4 mPa km–1)at the lower atmosphere level,as compared to that in Changchun(0.4 mPa km–1).The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance.The ozonsonde is expected to play an important role in operational observations of ozone profiles.展开更多
文摘碳点(CDs)因其较大的比表面积和较快的电子转移特性,已成为能量转换应用领域一种新兴的纳米炭材料。本文以低成本的石油焦为原料,通过简便的一步电化学刻蚀方法制备了硼氮双掺杂碳点(BN-CDs)。与单掺杂碳点B-CDs和N-CDs相比,双掺杂BN-CDs表现出更优异的四电子氧还原电催化活性,具有更正的起始电位(Eonset=0.958 V)和大的扩散极限电流密度(j D=-4.32 mA cm~(-2)),且长期稳定性和甲醇耐受性优于商用Pt/C催化剂。密度泛函理论计算(DFT)研究表明,B、N双掺杂的协同效应促进了O_2分子的吸附,有助于提高碳点的电催化活性。本研究为纳米炭材料的设计及其在能量转换领域的应用提供了新的思路。
基金supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.XDB05020503)the Special Fund for Public Welfare Industry (Meteorology) (Grant No.GYHY201106041)
文摘To make a detailed test on the reliability and detection performance of the electrochemical concentration cell(ECC)type ozonesonde which had been developed and preliminarily evaluated by the authors,an intensive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013.The results showed that the mean background current and its standard deviation were 0.03(0.04)μA and 0.02(0.03)μA in Beijing(Changchun).The average response time and its standard deviation were 27.8 s(30.4 s)and 4.0 s(3.7 s)in Beijing(Changchun).The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer.Large variation in ozone partial pressure was observed at the middle levels of the atmosphere(10–17 km).A more marked gradient of ozone change was observed in Beijing(3.4 mPa km–1)at the lower atmosphere level,as compared to that in Changchun(0.4 mPa km–1).The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance.The ozonsonde is expected to play an important role in operational observations of ozone profiles.
