V掺杂对Ni-Co-S/细菌纤维素基碳气凝胶电催化性能的影响

本研究以细菌纤维素基碳气凝胶(CA)为载体材料, 通过水热法制备了Ni-Co-S/CA复合气凝胶, 掺入钒元素调控材料的微观结构和性能。研究结果表明: Ni-Co-S的主要物相为NiCo₂S₄, 次相为NiS₂。随着镍钴盐浓度的增大, 负载量增加, 电催化峰电流密度先升后降。当镍钴盐浓度较低时, 掺微量钒后, Ni-Co-S从结晶度较高的球形颗粒转变成低结晶度的方形微粒, 电催化活性和稳定性都得到改善。在0.01 mol/L镍钴盐溶液中掺入3mol% V, 制备的电极对甲醇具有最优的催化氧化性能, 与不掺V的样品相比, 其峰电流密度(78.18 mA/cm ²)提升了至少45.7%。Ni-Co-S/CA复合气凝胶电极具有轻质、高孔隙率等优点, 有望用于便携式直接甲醇燃料电池。

Effect of V Doping on Electrocatalytic Performance of Ni-Co-S on Bacterial Cellulose-derived Carbon Aerogel

Ni-Co-S/CA composite aerogels were prepared by hydrothermal method using bacterial cellulose-derived carbon aerogels (CA) as support. The microstructure and properties of the composites were adjusted via adding trace vanadium. The characterization results show that the main phase of Ni-Co-S is NiCo₂S₄ with the secondary phase of NiS₂. With the increment of the nickel-cobalt salt concentration, the load amount increases, and the peak current density of electrocatalysis firstly upgraded and then degraded. After being doped with a small amount of vanadium at lower nickel-cobalt salt concentration, Ni-Co-S transforms from spherical particles with high crystallinity to square particles with low crystallinity, and its electrocatalytic activity and stability are improved. Under the preparative conditions of 0.01 mol/L total concentration of nickel-cobalt salt and 3mol% vanadium salt, the as-obtained electrode exhibits the optimal catalytic performance for methanol oxidation. Compared with the sample without V doping, its peak current density (78.1 mA/cm ²) enhanced by 45.7% at least. The Ni-Co-S/CA composite aerogel electrodes with the advantages of light weight and high porosity, is expected to be applied in portable direct methanol fuel cell.