Milli q3 system

Ammonium tungstate hydrate ((NH₄)₁₀H₂(W₂O₇)₆, 99.99%), ammonium molybdate tetrahydrate ((NH₄)₆Mo₇O₂₄·4H₂O, 99.0%), thiourea (CS(NH₂)₂, 99.0%) and tin tetrachloride hydrate (SnCl₄·5H₂O, 99.9%) were purchased from Sigma-Aldrich (Shanghai, China). Ethanol (C₂H₅OH, ACS, 99.9%) was purchased from J&K chemical (Shanghai, China). The gaseous analytes (CH₃COCH₃, (CH₃CH₂)₂O, CH₃CH₂CHO, C₆H₅CH₃, and NO₂) which were diluted with N₂ gas at concentrations of 1000 ppm were purchased from Nanjing Teqi Co., Ltd. All chemicals were used as received without further purification. The deionized (DI) water was purified using Milli-Q3 System (Millipore, France).

Titanium aluminum carbide (Ti₃AlC₂, ≥98%) was purchased from Tianmazhihui Technology Company (Beijing, China). Potassium hydroxide (KOH, 85%), hydrogen fluoride (HF, 40%) and Ni(ii) chloride hexahydrate (99.9%) were purchased from J&K Chemical (Beijing, China). 1,4-Naphthalene dicarboxylic acid (1,4-H₂NDC, 95%) was purchased from Aladdin (Shanghai, China). N,N-Dimethylformamide (DMF, 99.5%) and ethanol (99.7%) were purchased from Shanghai Chemical Reagent CO., LTD (Shanghai, China). Iridium oxide (IrO₂, 99.9%), Nafion and Co(ii) chloride hexahydrate (99.9%) were purchased from Sigma-Aldrich (Beijing, China). Iron(iii) chloride hexahydrate (97%) was purchased from Stream Chemicals, INC. (Newburyport, USA). N,N-Dimethyltetradecylamine (90%) was purchased from Tokyo Chemical Industry CO., LTD. (Tokyo, Japan). n-Butanol (99%) was purchased from Shanghai Shenbo Chemical CO., LTD. (Shanghai, China). BiVO₄ coated fluorine-doped SnO₂ (FTO) glass substrates with a BiVO₄ mass loading of 0.5 mg cm⁻² were purchased from TOEI Technology (Hangzhou, China). The deionized (DI) water was purified using a Milli-Q3 System (Millipore, France). All chemicals were used without further purification.