▎ 摘　　要

An integrated assembled recyclable catalytic material was fabricated by grafting Shewanella xiamenensis (S. xiamenensis) onto poly(vinyl alcohol)/graphene oxide films (denoted as S. xiamenensis GO/PVA biofilms) with different GO-to-PVA mass ratios (i.e., 4:1, 2:1, 1:1, 1:2, and 1:4 in 10 mg of GO-PVA mixtures). During a 48 h test, the S. xiamenensis GO/PVA biofilms demonstrated increased Cr(VI) removal efficiency of up to 100% for 50 mg/L Cr(VI). Moreover, the assembled films displayed desirable biocompatibility, satisfactory catalysis of Cr(VI) removal, and outstanding recyclability in reaction cycles (over 10 runs). The complete removal of Cr(VI) in the presence of S. xiamenensis GO/PVA biofilms required approximately 924 h, compared with 48 h for the control group. In addition, the catalytic efficiency was gradually increased during recycling owing to the greater biomass accumulation on the films' surface for each circular reaction. Moreover, GO was modified and evolved owing to the microbial activity of S. xiamenensis and eventually exhibited characteristics similar to those of reduced graphene oxide (rGO) (which could serve as an electron shuttle). The dual changes could synergistically facilitate the extracellular electron transfer governed by the direct contact mechanism as well as by the electron shuttle. Shewanella xiamenensis GO/PVA biofilms outperformed conventional catalysis and could represent a promising technology for the remediation of Cr(VI)-polluted wastewater or soils.