Mohamed Shaimaa K, Bashat Amany M A, Hassan Hassan M A, Ismail Nahla, El Rouby Waleed M A
Department of Chemistry, Faculty of Science, Suez University 43518 Suez Egypt
Physical Chemistry Department, Centre of Excellence for Advanced Sciences, Renewable Energy Group, National Research Centre Dokki 12311 Giza Egypt.
RSC Adv. 2023 May 9;13(20):14018-14032. doi: 10.1039/d3ra02011h. eCollection 2023 May 2.
Water splitting using photoelectrochemical (PEC) techniques is thought to be a potential method for creating green hydrogen as a sustainable energy source. How to create extremely effective electrode materials is a pressing concern in this area. In this work, a series of Ni/TiO anodized nanotubes (NTs) and Au/Ni/TiONTs photoanodes were prepared by electrodeposition cyclic voltammetry and UV-photoreduction, respectively. The photoanodes were characterized by several structural, morphological, and optical techniques and their performance in PEC water-splitting for oxygen evolution reaction (OER) under simulated solar light was investigated. The obtained results revealed the nanotubular structure of TiONTs was preserved after deposition of NiO and Au nanoparticles while the band gap energy was reduced allowing for effective utilization of solar light with lower charge recombination rate. The PEC performance was monitored and it was found that the photocurrent densities of Ni/TiONTs and Au/Ni/TiONTs were 1.75-fold and 3.25-fold that of pristine TiONTs, respectively. It was confirmed that the performance of the photoanodes depends on the number of electrodeposition cycles and duration of photoreduction of gold salt solution. The observed enhanced OER activity of Au/Ni/TiONTs could be attributed to the synergism between the local surface plasmon resonance (LSPR) effect of nanometric gold which increased solar light harvesting and the p-n heterojunction formed at the NiO/TiO interface which led to better charge separation and transportation suggesting its potential application as an efficient and stable photoanode in PEC water splitting for H production.
利用光电化学（PEC）技术进行水分解被认为是一种生产绿色氢气作为可持续能源的潜在方法。如何制备极其有效的电极材料是该领域的一个紧迫问题。在这项工作中，分别通过电沉积、循环伏安法和紫外光还原制备了一系列Ni/TiO阳极氧化纳米管（NTs）和Au/Ni/TiONTs光阳极。通过多种结构、形态和光学技术对光阳极进行了表征，并研究了它们在模拟太阳光下PEC水分解析氧反应（OER）中的性能。所得结果表明，在沉积NiO和Au纳米颗粒后，TiONTs的纳米管结构得以保留，同时带隙能量降低，使得太阳光能够得到有效利用，电荷复合率降低。对PEC性能进行了监测，发现Ni/TiONTs和Au/Ni/TiONTs的光电流密度分别是原始TiONTs的1.75倍和3.25倍。证实了光阳极的性能取决于电沉积循环次数和金盐溶液光还原的持续时间。观察到的Au/Ni/TiONTs增强的OER活性可归因于纳米金的局域表面等离子体共振（LSPR）效应增强了太阳光的捕获，以及在NiO/TiO界面形成的p-n异质结导致了更好的电荷分离和传输，这表明其在PEC水分解制氢中作为高效稳定光阳极的潜在应用。
