Electrocatalysts play a prominent role in the renewable energy conversion and storage applications, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and carbon dioxide reduction (CO2RR). Here we will briefly introduce our recent work in developing some of these electrocatalysts [1-5], together with theoretical calculations for rational structure designs and reaction mechanism understandings. Several representative examples using earth-abundant metal (hydro)oxides and carbons include: (1) hybrid hydroxide nanowire-nanoflake assembly for bifunctional HER/OER, (2) metal oxide@carbon superlattices for bifunctional HER/OER, (3) mesoporous oxide@carbon for bifunctional ORR/OER, and (4) tuning of nitrogen doping types in carbon nanostructures for CO2RR. Attributed to their high electrochemically active surface area, fast charge transport, efficient mass transfer and gas release, these nanostructured electrocatalysts enable much enhanced activity, such as reduced overpotentials, high current densities and long stability. In addition, we also demonstrate that by reversing the catalyst design concepts, new battery electrodes with substantially enhanced energy storage density and power density can also be realized .
(1) Li, J.; Wang, Y.; Zhou, T.; Zhang, H.; Sun, X.; Tang, J.; Zhang, L.; Yang, Z.; Zheng, G. F. J. Am. Chem. Soc. 2015, 137, 14305-14312.
(2) Cha, M.; Da, P.; Wang, J.; Wang, W.; Chen, Z.; Xiu, F.; Zheng, G. F.; Wang, Z. S. J. Am. Chem. Soc. 2016, 138, 8581-8587.
(3) Wang, Y.; Chen, L.; Yu, X.; Wang, Y. G.; Zheng, G. F. Adv. Energy Mater. 2017, 7, 1601390.
(4) Kuang, M.; Wang, Q.; Han, P.; Zheng, G. F. Adv. Energy Mater. 2017, 7, 1700193.
(5) Kuang M.; Han, P.; Qang, Q.; Li, J.; Zheng, G. F. Adv. Func. Mater. 2016, 26, 8555-8561.
(6) Wang, Y.; Cui, X.; Zhang, Y.; Zhang, L.; Gong, X. G.; Zheng, G. F. Adv. Mater. 2016, 28, 7626-7632.