Angew. Chem.：硼掺杂调变CoP电子结构，提升电催化析氢性能

电解水制氢的原料来源丰富、产氢纯度高，且可与太阳能发电、风能发电等系统联用，是当前的一个重要研究方向。目前，铂基材料仍是电催化析氢反应（HER）活性最高的电催化剂，但资源的稀缺性与高成本极大地限制了其在大规模解水产氢的上的应用。开发新型的高效非贵金属催化剂，是实现大规模电催化分解水制氢的关键。近年，过渡金属磷化物（TMPs）由于其具有优良导电性、机械强度、化学耐受性和低成本等优点而备受关注。如何进一步激活TMPs的催化活性，提升其在制氢应用中的潜力，对推动氢能的利用具有重要意义。

近日，黑龙江大学陈志敏教授（点击查看介绍）团队设计开发了一种新颖的碳纳米管负载硼（B）掺杂CoP纳米粒子的电催材料（B-CoP/CNT）。研究者们以硼氢化钠作为还原剂和硼源，通过静电组装、原位还原-退火和低温磷化过程获得了B-CoP/CNT复合材料。研究者们结合实验和理论计算发现，低电负性B掺杂原子可以改变与其相连Co和相邻P原子的局部电子构型，提高Co原子的电子离域能力以获得高电导率。同时局域电子结构调变也优化了活性位上H*吸附吉布斯自由能，使得材料拥有更好的HER动力学性能，实现宽pH高效稳定的电催化产氢。尤其是在中性和碱性介质中，大电流密度（>100 mA cm^-2）下，B-CoP/CNT优异的HER性能甚至超过了商用Pt/C。这项工作将为开发用于制氢的高活性非贵金属电催化剂开辟新的视角。

Figure 1. (a) Schematic illustration for the synthetic process of B-CoP/CNT hybrid. (b-g) TEM images, HRTEM images and STEM-EDX mapping of B-CoP/CNT hybrid. The inset in (b) SAED pattern of B-CoP/CNT hybrid.

Figure 2. (a-c) High-resolution Co 2p, B 1s, and P 2p XPS spectra of B-CoP/CNT and CoP/CNT hybrids, respectively. (d) Charge density distribution of CoP and B-CoP. (e) Co K-edge XANES spectra of B-CoP/CNT hybrid, CoP/CNT hybrid and several references, the inset is the pre-edge features of all samples. (f) Fourier transforms of k²-weighted EXAFS data for the Co K-edge of B-CoP/CNT hybrid, CoP/CNT hybrid and several references.

Figure 3. (a, b) iR-corrected HER polarization curves and the corresponding Tafel plots of B-CoP/CNT, CoP/CNT, phosphatized CNT and the commercial Pt/C (20%) catalysts recorded in 0.5 M H₂SO₄. The inserted images are the corresponding HER overpotential required for j = 10 mA cm^-2. (c, d) iR-corrected HER polarization curves and the corresponding Tafel plots of B-CoP/CNT and the commercial Pt/C (20%) catalysts recorded in 1.0 M PBS and 1.0 M KOH, respectively. (e) iR-corrected polarization curves recorded before and after 5000 accelerated degradation test CV cycles. (f) Nyquist plots of the B-CoP/CNT, CoP/CNT, and phosphatized CNT at open circuit potential in 0.5 M H₂SO₄, the inset is the equivalent circuit model applied to fit the Nyquist plots. (g) Optimized models for hydrogen adsorption at the Co-Co bridge site of CoP (101) with 10.3% B doping. (e) Free-energy diagram for HER. (f) Calculated DOS of surface Co atoms d orbitals on the pristine CoP (101) and CoP (101) surface with 10.3% B doping.

相关工作以研究论文的形式发表在Angew. Chem. Int. Ed.上。文章的通讯作者为黑龙江大学的陈志敏教授和任志宇教授，第一作者是黑龙江大学的硕士生曹二平。

原文（扫描或长按二维码，识别后直达原文页面，或点此查看原文）：

Boron-induced CoP electronic structure reformation drives remarkably enhanced pH-universal hydrogen evolution

Erping Cao, Zhimin Chen,* Hao Wu, Peng Yu, Ying Wang, Fei Xiao, Shuo Chen, Shichao Du, Ying Xie, Yiqun Wu and Zhiyu Ren*

Angew. Chem. Int. Ed., 2020, DOI: 10.1002/anie.201915254

导师介绍

陈志敏

https://www.x-mol.com/groups/chen_zhimin