Sodium sulfate na2so4

Pyrrole (reagent grade, 98.0%), polyacrylonitrile (PAN, M_w of ca. 150,000), polyvinylpyrrolidone (PVP, M_w of ca. 1,100,000), poly(vinylidene fluoride) (PVDF, M_w of ca. 500,000), poly(vinyl alcohol) (PVA, M_w of ca. 90,000), and 1-Methyl-2-pyrrolidinone (NMP, 99.0%) were obtained from Sigma-Aldrich Co. (Burlington, MA, USA). Sodium sulfate (Na₂SO₄, 98.5%) and dimethylformamide (DMF, 99.0%) were acquired from Samchun Chemical Company (Seoul, Republic of Korea). Iron(III) chloride hexahydrate (FeCl₃·6H₂O, 99.0%) and tin chloride pentahydrate (SnCl₄·5H₂O, 98.0%) were obtained from the Junsei Chemical Co. (Tokyo, Japan). Carbon black was purchased from Thermo Fisher Scientific (Waltham, MA, USA). All chemicals were used as received without any further reaction or treatment.

All materials were of analytical grade and were used without further purification. Nickel (II) acetate tetrahydrate (98%), titanium (IV) butoxide (97%), sodium molybdate dihydrate (≥99.5%), ethanol (EtOH), and acetylacetone were purchased from Sigma–Aldrich (St. Louis, MO, United States). Polyvinylpyrrolidone K90 (MW = 360,000) and thiourea (H₂NCSNH₂), obtained from Wako Pure Chemical Industries, Ltd (Osaka, Japan), were used in the synthesis of the NiTiO₃ NFs. Sodium sulfate (Na₂SO₄) and triethanolamine (TEOA) from Samchun Pure Chemical Co., Ltd (Pyeongtaek-si, Korea) were used in the measurement of electrochemical and photocatalytic properties. Conductive fluorine-doped tin oxide (FTO; 15 mΩ) glass with dimensions of 2 × 6 cm², purchased from Korea Fine Chemical Co., Ltd., was used as a substrate film.