*2.2. Preparation of Ag-Modified TiO<sup>2</sup> Thin Films on the Bamboo Surface*

The TiO<sup>2</sup> thin films were synthesized on the bamboo surface via a modified procedure according to our previous work [26]. In particular, the mixed solution of (NH4)2TiF<sup>6</sup> and H3BO<sup>3</sup> was sufficiently transferred into a 50 mL Teflon-lined autoclave without pH adjustment and heated at 90 ◦C for 4 h in an oven. A TiO<sup>2</sup> thin-film-coated bamboo sample was denoted as TB. Loading of Ag NPs on the surface of TB was achieved in the dark with a simple and rapid silver mirror method. Ammonia solution (25–28%) was added dropwise into 100 mL of AgNO<sup>3</sup> solution until the brown precipitate was dissolved. Then, a TB sample was submerged in the silver ammonia solution under feeble stirring for 1 h. Subsequently, the sample was transferred into a 0.2 M glucose solution until [Ag(NH3)2] + ions absorbed on the TB sample were completely reduced. Finally, the samples were repeatedly washed with deionized water and dried at 50 ◦C for 24 h in an oven. The Ag-NP-decorated TB samples were denoted as ATB-*x,* with *x* representing the solution concentration (5, 10, 30, 50, and 200 mM) of AgNO<sup>3</sup> as one of the raw materials. For example, ATB-10 indicates that the solution concentration of AgNO<sup>3</sup> was 10 mM, which was used to load the Ag NPs on the TB surface. Ag/bamboo (AB) samples were also prepared following the above-mentioned procedure.
