▎ 摘　　要

NOVELTY - Preparation of photothermal conversion polyvinyl alcohol (PVA)/reduced-graphene oxide (rGO)/wood aerogel composite hydrogel involves immersing the polished wood blocks in the delignification solution and heating to obtain log cellulose, decolorizing, washing to remove anhydrous ethanol, freezing, and then vacuum freeze-drying to obtain wood aerogels, dripping the precursor solution, removing excess PVA hydrogel precursor solution to obtain cellulose aerogel, dripping the PVA/GO hydrogel precursor solution on the surface of the cellulose aerogel to obtain the PVA/GO/wood aerogel precursor, adding the aerogel precursor into the mold and placing it in a liquid nitrogen bath, freezing, removing the gel and thawing it at room temperature, immersing it in deionized water until neutral to obtain PVA/GO/wood aerogel composite hydrogel, reducing, soaking in deionized water until neutral to obtain a directional ice-templated PVA/rGO/wood aerogel composite hydrogel, and freeze-drying. USE - Preparation of photothermal conversion PVA/rGO/wood aerogel composite hydrogel used in desalination of seawater (all claimed). ADVANTAGE - The method enables preparation of photothermal conversion PVA/rGO/wood aerogel composite hydrogel having excellent long-lasting stability, stable performance even after ten consecutive tests, salt removal rate above 99%, net evaporation rate of 2.32 kg.m-2.(hour)-1, and the energy conversion efficiency of up to 94%. DETAILED DESCRIPTION - Preparation of photothermal conversion polyvinyl alcohol (PVA)/reduced-graphene oxide (rGO)/wood aerogel composite hydrogel involves adding PVA and sodium dodecyl sulfate into deionized water, stirring magnetically until completely dissolved, then adding sulfuric acid solution and glutaraldehyde solution in sequence and stir to obtain a PVA hydrogel precursor solution, adding PVA and sodium dodecyl sulfate into deionized water, magnetically stirring until completely dissolved, then adding graphene oxide solution, stirring to fully mix the solution to obtain a PVA/GO hydrogel precursor solution, mixing deionized water, acetic acid and sodium chlorite to obtain a delignification solution, immersing the polished wood blocks in the delignification solution and heating at 85degrees Celsius for 12 hours to obtain log cellulose, decolorizing the log cellulose with ethanol, washing to remove anhydrous ethanol, freezing at -22degrees Celsius for 8 hours, and then vacuum freeze-drying at -43degrees Celsius for 48 hours to obtain wood aerogels, dripping the PVA hydrogel precursor solution onto the wood aerogel, removing excess PVA hydrogel precursor solution to obtain cellulose aerogel, dripping the PVA/GO hydrogel precursor solution on the surface of the cellulose aerogel to obtain the PVA/GO/wood aerogel precursor, adding the PVA/GO/wood aerogel precursor into the mold and placing it in a liquid nitrogen bath, moving the mold together with the mold to -22degrees Celsius for full crosslinking for 4 hours after the gel surface freezes and frost appears, removing the gel and thawing it at room temperature, immersing it in deionized water until neutral to obtain PVA/GO/wood aerogel composite hydrogel, then, placing in a hydrazine hydrate reducing solution, reducing at 85degrees Celsius for 2 hours, and then soaking in deionized water until neutral to obtain a directional ice-templated PVA/rGO/wood aerogel composite hydrogel, freeze-drying the PVA/rGO/wood aerogel composite hydrogel by freezing it with liquid nitrogen, and swelling the product in hot water at 85degrees Celsius for 2 hours.