Efficient production of acetate from inorganic carbon (HCO3–) in microbial electrosynthesis systems incorporating Ag3PO4/g-C3N4 anaerobic photo-assisted biocathodes

Mixotrophic bacteria for environmental detoxification of contaminated waste and wastewater

“…For example, the electrotrophs in microbial electrosynthesis systems (MES) take up electrons from solid-state cathode electrodes and use them within their metabolism to convert inorganic carbon (e.g., CO2) into complex chemical compounds (e.g., acetate) (Cai et al, 2020;Kong et al, 2021). After a brief introduction of the most representative classes of mixotrophic bacteria, their physiology, evolutionary origin, and their contribution to elemental biogeochemical cycles, this review summarizes the progressive role exerted by mixotrophic bacteria in conventional bioprocesses.…”

α-Fe2O3/g-C3N4 Z-Scheme Heterojunction Photocathode to Enhance Microbial Electrosynthesis of Acetate from CO2

“…In addition, the oxidative holes generated in the VB of α-Fe 2 O 3 directly combined with the electrons from the anode, providing additional driving force and reducing electron transfer resistance on the cathode surface and allowing more electrons to transfer to microorganisms through direct and indirect electron transfer via H 2 . Compared with Ag 3 PO 4 /g-C 3 N 4 for the MES with Serratia marcescens , they both had low VB (2.32 eV for α-Fe 2 O 3 and 2.61 eV for Ag 3 PO 4 ) for g-C 3 N 4 , and thus, binding electrons from the anode is easier. However, α-Fe 2 O 3 has a wide abundance on earth and is an environmentally friendly iron oxide.…”

“…Photoelectrode-assisted MES was first reported in 2015 through the introduction of a Si nanowire photocathode and a TiO 2 photoanode . Subsequently, WO 3 /MoO 3 /g-C 3 N 4 and Ag 3 PO 4 /g-C 3 N 4 heterojunction photocatalysts were used to promote acetate production in MES with Serratia marcescens . , Photoinduced electrons in the photocathode were used to generate H 2 and improve indirect ETR. Furthermore, the same research group determined that MnFe 2 O 4 /g-C 3 N 4 heterojunction with more negative conduction band edges for H 2 generation via photoreduction can enhance acetate production .…”

Microbial electrosynthesis: carbonaceous electrode materials for CO2 conversion

“…g-C3N4 is a classic polymer semiconductor that is broadly used in photocatalysis because of such advantages as superior chemical stability, relative affordability, and sustainable visible light response 79 . Recently, Serratia marcescens Q1 was used as the biocatalyst to build photo-assisted biocathodes such as WO3/MoO3/g-C3N4 and Ag3PO4/g-C3N4 with Z-scheme heterojunctions 81,82 . The light-harvesting capability and acetate…”