Bi no3 3 5h2o

Bi(NO₃)₃·5H₂O(≥99.0%), NH₄VO₃(≥99.0%), NaCl(≥ 99.8%), NH₃·H₂O(~28%), HNO₃(~68%), HBO₃(≥99.8%), KOH(≥85.0%), Na₂SO₃(≥ 97.0%), Co(NO₃)₂·6H₂O (≥98.5%), KMnO₄(≥ 99.5%), SrCO₃(≥99%), TiO₂(≥99%), Rh₂O₃(≥ 99.8%), RuCl₃·nH₂O(≥98%), K₂CrO₄(≥98%), polyvinyl alcohol(≥99%), Zn(NO₃)₂·6H₂O(≥99%), Na₂WO₄·2H₂O(≥99.5%), HCl(36.0~38.0%), (NH₄)₂C₂O₄·H₂O(≥99.8%), CuSO₄·5H₂O(≥99%), lactic acid_, NaOH(≥96%)_, and TiCl₄(≥98.0%) were purchased from Sinopharm Chemical Reagent Co., Ltd. ZnO (99.9%), Cu₂O(99.9%), WO₃ (≥99.0%) and low-melting-point liquid metal (bismuth indium tin ingot/Field’s metal, Bi: In: Sn = 32.5: 51: 16.5 wt%) is purchased from Thermo Fisher Scientific Inc. All chemicals were used without further purification.

The reactant materials to synthesize BiOCl spiral nanosheets, Bi(NO₃)₃·5H₂O (99%) and ethylene glycol (EG, 99%) were purchased from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). Poly(diallyldimethylammonium chloride) (PDDA, 20 wt% in water, MW = 400,000–500,000) and tetracycline (TC) were obtained from Aladdin. All chemicals were used as received without further purification. Ultrapure water (18.2 MΩ cm⁻¹) was used in all the experiments. In a typical synthesis process of BiOCl spiral nanosheet, 4.8 ml (1.13 wt%) PDDA was added in 80 ml of EG at room temperature with continuous stirring, and then 0.0971 g (0.2 mM) Bi(NO₃)₃ 5H₂O was dissolved in the above solution. The mixture was stirred for 30 min and further heated to 200 °C in a 250 ml two-neck flask equipped with a reflux condenser. After the temperature maintained at 200 °C for 2 h, and the mixture was cooled down to room temperature naturally. The white products were collected by centrifugation, washed with deionized water three times to remove residual ions, and finally dried at 60 °C overnight in vacuum. For comparison purpose the preparation of BiOCl bulk sample were carried out using the method reported^{58 (link)}.

Pd_x/Bi₂O₃/TiO₂ (x is the nominal molar ratio of Pd to Bi) catalysts were prepared by a two-step photo-deposition method using a high-pressure Xe lamp (300 W) as the light source. Typically, 100 mg of TiO₂ and 11.6 mg of Bi(NO₃)₃·5H₂O (Sinopharm chemicals, 99%) were dispersed in 4 mL of ethylene glycol in a Pyrex glass reactor. Prior to ultraviolet irradiation for 1 h, the suspension was bubbled with Ar for 30 min to eliminate dissolved O₂. Subsequently, 8 mL of PdCl₂ aqueous solution (the concentration is determined by x) was added into the suspension. After irradiation in Ar for another 1 h, the precipitates were collected by centrifugation, washed twice by water and ethanol, and then dried in an oven at 40 °C. When the sample was exposed in the air, Bi was oxidized to Bi₂O₃ spontaneously. The catalyst was activated by H₂ at 100 °C for 1 h and then cooled to RT in N₂ prior to the catalytic reaction and characterizations. The synthetic procedures of Bi₂O₃/TiO₂, Pd/TiO₂, Pd_1.0/Bi₂O₃/TiO₂-ox, PdBi/TiO₂, and Pd/Bi₂O₃ are presented in Supplementary Information.