Speaker
摘要
合理设计高活性、耐用的非贵金属电催化剂用于HER和OER反应具有重要的意义。本研究采用一步电沉积法制备了高性能的a-Ni3S2/Cu电催化剂。a-Ni3S2/Cu只需要1.49 V的超低槽电压就可以实现10 mA cm-2 的电流密度，超越了大多数先前报道的过渡金属基材料。a-Ni3S2与Cu耦合，电子从a-Ni3S2向Cu转移，优化了电子结构，Cu的d带中心上移，有利于反应中间体H的吸附。中毒实验，原位Raman也进一步证明了Cu为H吸附/脱附的活性位点。S周围聚集更多的正电荷，促进对水分子的活化。原位Raman, 原位EIS表明a-Ni3S2/Cu在反应过程中重构为活性物质NiOOH。进一步的中毒实验，甲醇氧化实验表明Ni为OER反应的活性位点，削弱了对含氧中间体的脱附自由能，大大提高了速率限制步骤（ O+OH-→OOH+e- ）的反应动力学。这一工作实现了零碳制氢技术的重大突破。
Abstract
It is important to design highly active and durable non-precious metal electrocatalysts for HER and OER reactions. In this study, a high performance A-Ni3S2 /Cu electrocatalyst was prepared by one-step electrodeposition. A-ni3s2 /Cu requires only an ultra-low tank voltage of 1.49 V to achieve a current density of 10 mA cm-2, exceeding most previously reported transition metal-based materials. a-Ni3S2 is coupled with Cu, electrons transfer from a-Ni3S2 to Cu, and the electronic structure is optimized. The D-band center of Cu moves upward, which is conducive to the adsorption of the reaction intermediate H. In situ Raman also further proves that Cu is the active site for H adsorption/desorption. More positive charges gather around S, promoting the activation of water molecules. In situ Raman and in situ EIS indicate that a-Ni3S2/Cu is reconstructed into the active material NiOOH during the reaction. Further poisoning experiments, methanol oxidation experiments showed that Ni was the active site of OER reaction, which weakened the desorption free energy of oxygen-containing intermediates and greatly improved the reaction kinetics of the rate-limiting step (O+OH-→OOH+e-). This work has achieved a major breakthrough in zero-carbon hydrogen production technology.
| 关键词 | 电解水、非晶/晶态异质结构、原位表征、DFT计算 |
|---|---|
| Keywords | water splitting amorphous/crystalline heterostructure in situ characterization DFT calculation |
