Pd增强缺陷态TiO_(2)纳米管阵列的光催化产氢性能

Pd-loaded Defective TiO_(2) Nanotube Arrays for Enhanced Photocatalytic Hydrogen Production Performance

通过光还原沉积法,利用氧空位诱导作用,在Ni掺杂的缺陷态TiO_(2)纳米管阵列(TNT-Ni)上得到金属Pd含量不同的Pd-TNT-Ni催化剂.采用场发射扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外-可见漫反射(UV-Vis DRS)、表面光电压(SPV)、光致发光光谱(PL)和电化学测试等表征手段,探究了Pd与Ni掺杂的缺陷态TiO_(2)纳米管阵列之间的强相互作用对其光吸收特性和载流子分离及传输效率的影响,阐明了强相互作用对材料光催化活性的调控机理,提出了Pd增强Pd-TNT-Ni光催化性能的作用机理.结果表明,通过光还原法制备的Pd纳米颗粒尺寸为10~20 nm的Pd_(120)-TNT-Ni样品的光响应值为4.22 mA/cm^(2),是未负载Pd样品光响应值(1.14 mA/cm^(2))的3.7倍,其具有最佳的平均产氢速率(5.16 mmol·g^(‒1)·h^(‒1)),是TNT样品平均产氢速率(0.45 mmol·g^(‒1)·h^(‒1))的12倍,表明Pd与缺陷态TiO_(2)纳米管阵列之间的强相互作用驱动了载流子的分离及传输,且Pd作为电子捕获势阱及反应活性位点,显著提高了材料的光催化性能.

Pd-TNT-Ni catalysts with different metal Pd contents were obtained on Ni-doped defective state TiO_(2) nanotube arrays(TNT-Ni)by photoreductive deposition method through oxygen vacancy induction.SEM,XPS,UV-Vis DRS,surface photovoltage(SPV),PL and electrochemical tests were employed to investigate the effect of strong interactions between Pd and Ni-doped defective state TiO_(2) nanotube arrays on their optical absorption proper⁃ties and carrier separation and transport efficiency.The modulation mechanism of strong interaction on the regulation of the photocatalytic activity of the material was elucidated,and the action mechanism of Pd-enhanced Pd-TNT-Ni photocatalytic performance was proposed.The results demonstrated that the Pd nanoparticles prepared by photoreduc⁃tion were 10—20 nm in size.The photoresponse of the Pd_(120)-TNT-Ni sample showed 4.22 mA/cm^(2),which was 3.7 times higher than that of the unloaded TNT-Ni sample(1.14 mA/cm^(2)).Meanwhile,Pd_(120)-TNT-Ni had the most excellent average hydrogen production rate(5.16 mmol·g^(‒1)·h^(‒1)),which was nearly 12 times higher than that of the TNT catalyst(0.45 mmol·g^(‒1)·h^(‒1)).It was shown that the strong interaction between Pd and defective TiO_(2) nanotube arrays drove carrier separation and transport,while Pd as an electron trap and reactive site significantly improved the photocatalytic performance of the material,which had implications for the design and preparation of semiconductor materials with high photocatalytic activity.