摘要
光电化学电池产氢过程中利用Na_2S/Na_2SO_3混合物作为电解质溶液稳定硫化物阳极通常会牺牲电流产氢效率(η_(current)).本文采用Na_2S/Na_2SO_3和p H中性的Na_2SO_4分别作为光解水电池的阳极和阴极电解液可有效抑制CuInS_2-In_2O_3-TiO_2(CIS-In_2O_3-TNT)纳米管杂化结构的光腐蚀,同时提高η_(current).通过脉冲辅助电沉积法可将n型CIS和In_2O_3纳米粒子沉积在TNT阵列表面,在保留TNT原有中空结构的前提下将纳米粒子均匀沉积在纳米管上对于在杂化结构中获得高效电荷聚集和分离非常必要.与Na_2S/Na_2SO_3单电解液电池相比双电解液的引入不仅提高了CIS-In_2O_3-TNT阳极的光稳定性,而且η_(current)接近于1并远高于单电解液电池(20%).
The utilization of Na2S/Na2SO3 mixture as the electrolyte solution to stabilize sulfide anode in a photoelectrochemical cell for hydrogen evolution generally compromises the current-to-hydrogen efficiency(ηcurrent) of the system. Here, the employment of a dual-electrolyte system,that is, Na2S/Na2SO3 mixture and p H-neutral Na2SO4 as the respective electrolyte solutions in the anode and cathode chambers of a water splitting cell is demonstrated to suppress the photocorrosion of CuInS2-In2O3-TiO2 nanotube(CISIn2O3-TNT) heterostructure, while simultaneously boosts theηcurrent. Although n-type CIS and In2O3 nanoparticles can be easily formed on TNT array via facile pulse-assisted electrodeposition method, conformal deposition of the nanoparticles homogeneously on the nanotubes wall with preservation of the TNT hollow structure is shown to be essential for achieving efficient charge generation and separation within the heterostructure. In comparison to Na2S/Na2SO3 solution as the sole electrolyte in both the anode and cathode chambers, introduction of dual electrolyte is shown to not only enhance the photostability of the CIS-In2O3-TNT anode, but also lead to near-unity ηcurrentas opposed to the merely 20% ηcurrentof the single-electrolyte system.
基金
supported by the Australian Research Council (DP170102895)