论文题目：Tailoring the d-band center of N-doped carbon nanotube arrays with Co4N nanoparticles and single-atom Co for a superior hydrogen evolution reaction
论文作者：Bo Cao, Minghao Hu, Yan Cheng, Peng Jing, Baocang Liu,Bo Zhou, Xi Wang, Rui Gao, Xiaolei Sun, Yaping Du*, Jun Zhang
A 3D self-supported integrated electrode, consisting of heteroatomic nitrogen-doped carbonnanotubearrays on carbon cloth with confined ultrafine Co4Nnanoparticles and a distribution of anchored single-atomCo, is fabricated via a cobalt-catalyzed growth strategy using dicyandiamide as the nitrogen and carbon source and a layered cobalt hydroxide-nitrate salt as the precursor. The abundance of exposed active sites, namely, theCo4Nnanoparticles, single-atomCo, and heteroatomic N-dopedcarbon nanotubes, and multiple synergistic effects among these components provide suitable tailoringofthed-bandcenterfor facilitating vectorial electron transfer and efficient electrocatalysis. Benefiting from the merits of its structural features and electronic configuration, the prepared electrode exhibits robust performance toward thehydrogenevolutionreactionwith overpotentials of only 78 and 86 mV at 10 mA cm(-2) in acidic and basic electrolytes, respectively. Density functional theory calculations and X-ray photoelectron spectroscopy valence band measurements reveal that the effective tailoringofthed-bandcenter by Co4Nnanoparticles plays a crucial role in optimizing thehydrogen adsorption free energy to a more thermoneutral value for efficient electrocatalysis.