Sodium sulfite

Bismuth nitrate pentahydrate (Bi(NO₃)₃·5H₂O, 99%), potassium iodide (KI, 99%), and p-benzoquinone (C₆H₄O₂, 99%) for the preparation of BVO in the experiment were from Aladdin (Shanghai, China). Vanadium acetylacetonate (C₁₀H₁₄O₅V, 99%) and vanadium pentoxide (V₂O₅, 99%) were from MACKLIN (Shanghai, China). The solvent used was nitric acid (HNO₃) from MACKLIN. Dimethyl sulfoxide (C₂H₆OS) was from Aladdin. Acetonitrile (CH₃CN) was obtained from Aladdin, sodium bicarbonate (NaHCO₃, ≥99.8%) and sodium carbonate (Na₂CO₃, ≥99.8%) were obtained from MACKLIN. Potassium hydroxide (KOH, 90%), sodium hydroxide, sodium sulfite, and boric acid (H₃BO₃, 99.99%) come from MACKLIN. Benzyl alcohol (C₆H₅CH₂OH, >99.0%) and benzaldehyde (C₇H₆O, >99.0%) are sourced from Aladdin.

Balsa wood with a density of ~94 mg cm⁻³ was used to fabricate the wood-based composite aerogels. The wood samples were cut to the dimensions of 30 × 30 × 5 mm³ (radial × tangential × longitudinal). The reagents, including methyltriethoxysilane (MTES, ≥98%), sodium chlorite (NaClO₂, 80%), acetic acid (AR), hydrochloric acid (HCl, AR), sodium sulfite (Na₂SO₃, AR), and sodium hydroxide (NaOH, AR) were bought from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). All of these chemicals were used as received without further purification. The de-ionized water was used to make up all mixed solutions and throughout the experiments.

All used chemicals are analytic grade reagents without further purification. Bismuth nitrate (Bi(NO₃)₃·5H₂O, AR), sodium tungstate (Na₂WO₄·2H₂O, AR) and sodium bicarbonate (NaHCO₃, AR), dimethyl sulfoxide (DMSO, AR) were acquired from Sinopharm Chemical Reagent Co., Ltd. Sodium sulfite (Na₂SO₃, AR was purchased from Shanghai Macklin Biochemical Co., Ltd. Carban dioxide (CO₂, ≥99.995%) was purchased from Soochow Jinhong Co., Ltd. Deuterium oxide (D₂O, ≥99.9%) was purchased from Qingdao Asfirst Science and trade Co., Ltd. ¹³CO₂ was bought from Soochow changyou gas Co., Ltd with purity of 99.9%. Deionized water was employed throughout the whole experiments.