Lu Tiantian, Sun Mingzi, Wang Fengmei, Chen Shan, Li Youzeng, Chen Jialei, Liao Xuelong, Sun Xiaoting, Liu Ying, Wang Fei, Huang Bolong, Wang Huan
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071, China.
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon 000000, Hong Kong SAR, China.
ACS Nano. 2024 Jun 11;18(23):15035-15045. doi: 10.1021/acsnano.4c01698. Epub 2024 May 26.
Two-electron oxygen reduction reaction (2e ORR) is of great significance to HO production and reversible nonalkaline Zn-air batteries (ZABs). Multiple oxygen-containing sp-bonded nanocarbons have been developed as electrocatalysts for 2e ORR, but they still suffer from poor activity and stability due to the limited and mixed active sites at the edges as well as hydrophilic character. Herein, graphdiyne (GDY) with rich sp-C bonds is studied for enhanced 2e ORR. First, computational studies show that GDY has a favorable formation energy for producing five-membered epoxy ring-dominated groups, which is selective toward the 2e ORR pathway. Then based on the difference in chemical activity of sp-C bonds in GDY and sp-C bonds in CNTs, we experimentally achieved conductive and hydrophobic carbon nanotubes (CNTs) covering O-modified GDY (CNTs/GDY-O) through a mild oxidation treatment combined with an in situ CNTs growth approach. Consequently, the CNTs/GDY-O exhibits an average Faraday efficiency of 91.8% toward HO production and record stability over 330 h in neutral media. As a cathode electrocatalyst, it greatly extends the lifetime of 2e nonalkaline ZABs at both room and subzero temperatures.
双电子氧还原反应（2e ORR）对于过氧化氢（HO）的生成以及可逆非碱性锌空气电池（ZABs）具有重要意义。多种含氧基sp键合的纳米碳已被开发用作2e ORR的电催化剂，但由于边缘处活性位点有限且混合以及亲水性，它们仍然存在活性和稳定性较差的问题。在此，研究了具有丰富sp-C键的石墨炔（GDY）用于增强2e ORR。首先，计算研究表明，GDY生成以五元环氧环为主的基团具有良好的形成能，这对2e ORR途径具有选择性。然后，基于GDY中sp-C键与碳纳米管（CNTs）中sp-C键化学活性的差异，我们通过温和氧化处理结合原位碳纳米管生长方法，实验实现了导电且疏水的碳纳米管覆盖O修饰的GDY（CNTs/GDY-O）。因此，CNTs/GDY-O在中性介质中对HO生成表现出91.8%的平均法拉第效率，并在330小时以上具有创纪录的稳定性。作为阴极电催化剂，它在室温和零下温度下都大大延长了2e非碱性锌空气电池的寿命。
