Bi2o3

Nanocomposites with SWCNTs and Bi₂Te₃ nanoplates were prepared via solvothermal synthesis. The outline of this process is shown in Supplementary Fig. S4. The system consisted of a Teflon-lined stainless-steel autoclave and a hot plate with a magnetic stirrer. We used Bi₂O₃ (Fujifilm Wako Pure Chemical Co., > 99.9%), TeO₂ (Kojundo Chemical Laboratory Co., Ltd., > 99.9%), ethylene glycol (Fujifilm Wako Pure Chemical Co., > 90.0%), polyvinyl pyrrolidone (PVP; Fujifilm Wako Pure Chemical Co., K30, M_s ~ 40,000), sodium hydroxide (NaOH; Fujifilm Wako Pure Chemical Co., > 97.0%), and SWCNTs (Zeon Co., ZEONANO SG101) to prepare the precursor liquid solution. The procedure for the synthesis of the nanocomposites was as follows: 0.4 g of PVP was dissolved in 18 mL of ethylene glycol, followed by the addition of Bi₂O₃ (20 mM), TeO₂ (70 mM), 2 mL of aqueous NaOH solution (0.5 M), and 1–12 mL of SWCNT-ethanol solution (0.2 wt%). The resulting precursor solution was sealed in an autoclave. The autoclave was then heated to 200 °C and maintained at that temperature for 4 h, while the solution was stirred at 500 rpm. After synthesis, the products were cooled naturally to below 50 °C. The products were collected by centrifugation and washed several times with distilled water and pure ethanol. Finally, they were dried under vacuum at 60 °C for 24 h.

CsCl (99.0%), NaCl (99.5%), Bi₂O₃ (99.99%), BiOCl (99.5%), Nb₂O₅ (99.9%), H₂PtCl₆ (99.9%), CH₃OH (99.8%), Pb(NO₃)₂ (99.9%), and MnSO₄·5H₂O (99.9%) were purchased from FUJIFILM Wako Pure Chemical Corporation. Rh(NO₃)₃ and Na₃RhCl₆ were purchased from Kanto Chemical Corporation. Sodium 2-sulfonate-1,3,5,7-tetramethyl-8-(3,4-dinitrophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (MS-DN-BODIPY) was synthesized according to the literature. Water was purified using a Milli-Q purification system (Direct-Q UV S.).