- A+
▲第一作者：陈晓悦
通讯作者：邵敏华、田健、韩野 通讯单位：山东科技大学、香港科技大学
本团队首次通过一步水热法在Ti3C2 MXene表面负载半金属1T'相MoS2 (1T'-MoS2/Ti3C2复合材料)作为一种高效的非贵金属固氮电催化剂。在0.1 M Na2SO4溶液中，1T'-MoS2/Ti3C2复合材料在-0.95 V vs. RHE时实现了31.96 µg h-1 mg-1cat.的高氨产率，在-0.70 V vs. RHE时达到了30.75%的法拉第效率(FE)，这比单独的纯1T'-MoS2和纯Ti3C2 MXene显著出色，也好于2H-MoS2/Ti3C2复合材料和1T-MoS2/Ti3C2复合材料。
▲Figure 1. Schematic diagram of preparation process for 1T'-MoS2/Ti3C2 composites.
图1为样品合成示意图。Ti3AlC2 MAX首先用HF蚀刻以去除Al层以获得Ti3C2 MXene。然后通过水热法引入1T'-MoS2纳米片，该纳米片锚定在Ti3C2 MXene上形成1T'-MoS2/Ti3C2复合材料。
▲Figure 2. XRD pattern of (a) bulk Ti3AlC2, Ti3C2 MXene and 1T'-MoS2/Ti3C2 composites with various loading of 1T'-MoS2 nanosheets (5, 7, 10 and 15 wt.% 1T'-MoS2); (b) 1T'-MoS2。 ▲Figure 3. SEM images of (a) Ti3AlC2, (b) Ti3C2 MXene and (c, d) 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2), respectively. (e) TEM images of 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2). (f) HRTEM images of 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2, the inset shows the magnification of the area enclosed by the orange square). ▲Figure 4. (a) Survey, (b) Ti 2p, (c) C 1 s, (d) O 1s, (e) Mo 3d and (f) S 2p XPS spectra of 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2). ▲Figure 5. (a) Linear sweep voltammetry (LSV) curves of 10 wt.% 1T'-MoS2/Ti3C2 composite materials recorded in N2-saturated (orange line) and Ar-saturated (black line) 0.1 M Na2SO4. (b) UV-vis absorption spectra of 0.1 M Na2SO4 electrolyte stained with indophenol indicator after electrolysis for 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2) at a series of potentials for 2 h. (c) NH3 yield rates and FEs of 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2) at a series of potentials. (d) 1H NMR spectra (400 MHz) of both 14NH4+ and 15NH4+ produced from the NRR reaction (at -0.95 V vs. RHE) using 14N2 or 15N2 as the N2 source. ▲Figure 6. (a) NH3 yield rates and FEs of 10 wt.% 1T'-MoS2/Ti3C2 composites at -0.95 V vs. RHE during recycling tests for 6 times; (b) NH3 yield rates and FEs of pure Ti3C2 MXene, pure 1T'-MoS2 and 1T'-MoS2/Ti3C2 composites with different content of 1T'-MoS2 (5, 7, 10 and 15 wt.%) at -0.95 V vs. RHE; (c) NH3 yield rates and FEs of 2H-MoS2/Ti3C2 composites (10 wt.% 2H-MoS2), 1T-MoS2/Ti3C2 composites (10 wt.% 1T-MoS2) and 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2); (d) NH3 yield rates and FEs of 1T'-MoS2/Ti3C2 composites (10 wt.% 1T'-MoS2) with different N2 flow rates. All experiments and tests are carried out under ambient conditions of normal temperature and pressure. ▲Figure 7. The configuration of the hetero-structure, (a) the directions and lengths of the Ti3C2 slab, (b), the directions and lengths of the 1T'-MoS2 slab, and (c) the model of 1T'-MoS2/Ti3C2 (color notation: light blue-Ti, brown-C, plump-Mo, and yellow-S). (d) Most stable configurations of reaction intermediates on the 1T'-MoS2 surface along the NRR alternating pathway Ti3C2 (color notation: light blue-Ti, brown-C, plump-Mo, yellow-S, blue-N, and pink-H). (e) Gibbs free energy diagram of the NRR alternating pathway on TiO2 and 1T'-MoS2/TiO2 surfaces at pH = 6 and URHE = -0.65 V.
未完待续
目前评论：0