Preparation of NiO by Simple Heat Treatment Method and its Application in Photocatalytic Water Splitting

Abstract

As a cocatalyst, NiO has shown a great potential in facilitating photocatalytic water splitting for hydrogen evolution. In this work, a new photocatalyst thin film (Ni/NiO/NaTaO3: La) is successfully prepared to optimize the performance of the photocatalytic water splitting. The NiO cocatalyst is prepared by a simple heat treatment method. An efficient heterojunction can be formed between NiO and NaTaO3, which is beneficial to the transmission and separation of photogenic carriers. The photocatalytic activity of Ni/NiO/NaTaO3: La is 10.83 µmol/h cm2 under high-pressure mercury lamp irradiation, which is two times higher than that of Ni/NaTaO3: La. In addition, the Ni/NiO/NaTaO3: La thin film is treated under different temperatures. It can be observed that annealing temperature has a great influence on the photocatalytic activity of Ni/NiO/NaTaO3: La thin film. When the sample annealed in 700 °C, the photocatalytic activity for water splitting is the highest, indicating the temperatures have an effect on the formation of NiO and photocatalytic efficiency. Our photocatalyst thin film (Ni/NiO/NaTaO3: La) provides sustainable photocatalysts by taking both photocatalyst stability and repeated utilization into consideration. More importantly, this work also provides a new insight into the synthesis of Ni/NiO/NaTaO3: La thin film, which has a great application prospects in the field of photocatalytic water splitting. NiO cocatalyst is prepared by a simple heat treatment method and this novel photocatalyst thin film (Ni/NiO/NaTaO3: La) is successfully prepared to optimize the performance of the photocatalyst.