Ahmad Irshad, Akhtar Muhammad Shoaib, Ahmed Ejaz, Ahmad Mukhtar, Naz Muhammad Yasin
Department of Physics, Bahauddin Zakariya University, Multan 60800, Pakistan.
School of Computer and Communication, Lanzhou University of Technology, Lanzhou 10731, China.
J Colloid Interface Sci. 2021 Feb 15;584:182-192. doi: 10.1016/j.jcis.2020.09.116. Epub 2020 Oct 6.
We report high photocatalytic hydrogen evolution from water-glycerol mixture under visible light illumination using sol-gel method synthesized zinc oxide (ZnO), Lutetium (Lu) modified ZnO and Lu modified ZnO/CNTs composite. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), Brunauer-Emmett-Teller (BET), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), photocurrent transient response and electrochemical impedance spectroscopy (EIS) Nyquist studies were used to determine the reason for improved photocatalytic hydrogen evolution. The highest hydrogen evolution rate of 380 µmolh was obtained for Lu modified ZnO/CNTs composite, 3.11 times the amount generated over Lu modified ZnO and 10.5 times than using pure ZnO sample. This efficient enhancement in the photocatalytic hydrogen evolution was apparently attributed to the red shift in the optical absorption, increased charge separation, high surface area, cleavage of glycerol by Lu and synergistic effect between Lu and CNTs. Moreover, the effect of Lu and CNTs loading on the photocatalytic hydrogen evolution activity of Lu modified ZnO/CNTs was also studied under analogous experimental conditions. A mechanism of photocatalytic hydrogen evolution by Lu modified ZnO/CNTs composite was also proposed. Additionally, synthesized samples showed prolonged photostability with steady hydrogen evolution in successive cycle runs. This report might attract much attention to design highly efficient and inexpensive photocatalyst for hydrogen evolution under visible light illumination.
我们报道了使用溶胶-凝胶法合成的氧化锌（ZnO）、镥（Lu）改性的ZnO以及Lu改性的ZnO/碳纳米管（CNTs）复合材料，在可见光照射下从水-甘油混合物中实现了高光催化析氢。利用X射线衍射（XRD）、透射电子显微镜（TEM）、能量色散X射线（EDX）、布鲁诺尔-埃米特-泰勒（BET）、紫外-可见漫反射光谱（UV-Vis DRS）、光致发光（PL）、X射线光电子能谱（XPS）、光电流瞬态响应以及电化学阻抗谱（EIS）奈奎斯特研究来确定光催化析氢性能提高的原因。Lu改性的ZnO/CNTs复合材料的析氢速率最高，为380 μmol/h，是Lu改性的ZnO析氢量的3.11倍，是纯ZnO样品的10.5倍。光催化析氢效率的显著提高显然归因于光吸收的红移、电荷分离增加、高比表面积、Lu对甘油的裂解以及Lu和CNTs之间的协同效应。此外，在类似实验条件下还研究了Lu和CNTs负载量对Lu改性的ZnO/CNTs光催化析氢活性的影响。还提出了Lu改性的ZnO/CNTs复合材料光催化析氢的机理。此外，合成的样品在连续循环运行中表现出延长的光稳定性和稳定的析氢性能。本报告可能会引起人们对设计高效且廉价的可见光照射下析氢光催化剂的广泛关注。
