花状形貌TiO2-NTs@Sb-SnO2电极的脉冲电沉积法制备及电催化性能研究

目的通过引入TiO_2纳米管中间层,增加表面活性层与基体的接触和活性物质的负载量,提高电极的稳定性。通过表观形貌构建,增加电极的活性比表面积,提高Sb-SnO_2电极的电催化性能。方法采用TiO_2纳米管阵列(TiO_2-NTs)作中间层,通过两阶段脉冲电沉积法,构建了新型多层次花状形貌的Sb-SnO_2电极。通过调整脉冲信号,实现对电极形貌的控制。结果通过阳极氧化法,在Ti基体表面得到了均一的TiO_2纳米管阵列结构。在电极制备过程中,采用反向脉冲电沉积(8 ms,833 m A/cm2;2 ms,-833 m A/cm2;0.99 s,0 A),得到了均匀的管套管结构,继而得到了TiO_2-NTs@Sb-SnO_2的致密层。通过施加脉冲信号(5 ms,200m A/cm2;195 ms,0 m A/cm2),获得了花状形貌。电化学测试显示,电极的析氧电位达到2 V(vs.SCE),苯酚氧化峰出现在1.7 V左右,电极的电荷传递阻抗为50.4?,加速寿命结果可达到39 h。电化学苯酚降解测试显示,4 h电化学降解后,TiO_2-NTs@Sb-SnO_2电极对苯酚的去除率达到97%,苯酚降解的一级动力学速率常数为14.9×10-3 min-1。结论脉冲电沉积制备的电极具有良好的稳定性和良好的苯酚电催化去除性能。

Pulse Electrodeposition Fabrication and Electro-catalytic Property of Flower-like Sb-SnO2 on TiO2 Nanotubes

The work aims to improve contact between surface active layer and substrate,capacity of active substance as well as stability of electrode by introducing active substance nanotube interlayer,and enhance active specific surface area of electrode and electrocatalytical activity of Sb-SnO2 electrode by constructing apparent morphology.With TiO2 nanotube arrays as the interlayer,novel hierarchical flower-like Sb-SnO2 electrode was fabricated in the method of two-stage pulse electrodeposition.Highly ordered TiO2 nanotube array was obtained on the surface of Ti substrate in the method of anodic oxidation.During the preparation process,reverse pulse electrodeposition (8 ms,833 mA/cm2;2 ms,-833 mA/cm2;0.99 s,0 A) was completed to construct distinct tube-in-tube structure and further compact Sb-SnO2-coated TiO2-NTs layer.Pulse signal (5 ms,200 mA/cm2;195 ms,0 mA/cm2) was applied to obtain flower-like morphology.Electrochemical test showed that oxygen evolution potential of the electrode was 2.0 V (vs.SCE) and phenol oxidation peak appeared at nearly 1.7 V,charge transfer resistance was 50.4 Ω and accelerated life result could be up to 39 h.Electrochemical phenol degradation test showed that the TiO2-NTs@Sb-SnO2 could remove 97％ of phenol after 4 h electrochemical degradation,and first-order kinetic rate constant of phenol degradation was 14.9× 10-3 min-1.An electrode prepared in the method of pulse electrodeposition exhibits good stability and electrocatalytic removal capacity of phenol.