Designing ZnBi₂O₄/ZIF-67 Derived Hollow Co₃O₄ Decorated Reduced Graphene Oxide: A Hybrid Nanocatalyst with Boosted Visible-Light Photocatalytic Activities

Abstract

Extensive investigations have been conducted to explore the photocatalytic degradation of economically harmful substances, employing a wide range of photocatalytic materials and various approaches. The successful degradation and elimination of persistent pollutants from aquatic environments remain a challenging task, requiring further advancements in efficiency. Hereby, we present a ZnBi 2 O 4 /ZIF-67 derived hollow Co 3 O 4 decorated reduced graphene oxide (rGO) hybrid nanocatalyst (ZnBi 2 O 4 /ZIF-Co 3 O 4 /rGO:ZCG) fabricated through a facile thermal treatment approach. The synthesized ZCG heterojunction demonstrated exceptional catalytic effectiveness for the photocatalytic reduction of Cr(VI) and photocatalytic degradation of rhodamine B (RhB) when exposed to visible radiation. A comprehensive array of analytical techniques was employed to thoroughly characterize the produced photocatalyst. In the realm of photocatalytic efficiency, ZCG-4 beats all other catalytic materials in eradicating model contaminants. Based on our outcomes, the ZCG-4 nanohybrid can reduce 97.4% (20 ppm, 60 min) of Cr(VI) to Cr(III), and degraded 92.5% (20 ppm, 120 min) of RhB, which is more superior to pristine and doublet nanohybrids. The improved photocatalytic Cr(VI) reduction and RhB degradation may be attributed to the beneficial synergistic interaction between the rGO, ZnBi 2 O 4 , and ZIF-Co 3 O 4 nanocomponents in the nanohybrid. Based on the data from the various experiments, we infer that the as-prepared photocatalyst functions via a Z-scheme charge transfer channelization mechanism, exhibiting a significant suppression of the photogenerated electron−hole pairs charge recombination. In addition, after five cycles of recycling, there is no obvious decline in the ZCG photocatalytic ability to catalyze Cr(VI) and RhB. This research demonstrates that the as-obtained ZCG nanocatalysts have significant potential for effectively addressing the issue of environmental remediation of toxic pollutants.