2.1 Materials and chemicals
Ti3AlC2 powder (200 mesh) was purchased from Laizhou Kaien Ceramic Materials Co., Ltd. HCl (36~38%) was purchased from Guangzhou Chemical Reagent Co., Ltd. LiF (99.9%) was provided by Aladdin Reagent Co., Ltd. Anhydrous ethanol (99.9%) was purchased from Guangzhou Donghong Reagent Co., Ltd. Multi-walled carbon nanotubes (CNTs) were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. On-site deionized water was obtained from ELGA Lab Water Purification Systems. A stainless steel cleaning agent was provided by Shenzhen Xinchangyuan Chemical Co., Ltd. Nanjing Gaoqian Functional Materials Technology Co., Ltd. provided the tubular porous stainless steel substrates (Φ8 mm × δ2 mm × l 500 mm) with an average pore size of 2 μm, which can be cut to the desired length.