Flower ball cathode assembled from Cu doped Co3S4/Ni3S2 ultrathin nanosheets in a photocatalytic fuel cell for efficient photoelectrochemical rifampicin purification and simultaneous electricity generation based on a CuO QDs/TiO2/WO3 photoanode.

Herein, an efficient CuO QDs/TiO2/WO3 photoanode and a Cu doped Co3S4/Ni3S2 cathode were successfully synthesized. The optimized CuO QDs/TiO2/WO3 photoanode achieved a photocurrent density of 1.93 mA cm-2 at 1.23 vs. RHE, which was 2.27 times that of a WO3 photoanode. The CuO QDs/TiO2/WO3-buried junction silicon (BJS) photoanode was coupled with the Cu doped Co3S4/Ni3S2 cathode to construct a novel photocatalytic fuel cell (PFC) system. The as-established PFC system showed a high rifampicin (RFP) removal ratio of 93.4% after 90 min and maximum power output of 0.50 mW cm-2. Quenching tests and EPR spectra demonstrated that ˙OH, ˙O2- and 1O2 were the main reactive oxygen species in the system. This work provides a possibility to construct a more efficient PFC system for environmental protection and energy recovery in the future.

New g-C3N4/GO/MoS2 composites as efficient photocatalyst for photocathodic protection of 304 stainless steel.

Photocathodic protection is an economical and environmental metal anticorrosion method. In this research, we successfully synthesized the g-C3N4/GO (15 wt%)/MoS2 catalytic materials by a facile hydrothermal method. The results show that the as-prepared g-C3N4/GO (15 wt%)/MoS2 composites prominently enhanced photocatalytic activities for the photocathodic protection of 304 stainless steel (SS) compared with the corresponding pristine g-C3N4 and MoS2. Notably, the AC impedance results demonstrated that the Rct value of 304 SS coupled with g-C3N4/GO (15 wt%)/MoS2 decreased to 35.66 Ω•cm2, which is 29 and 37 times lower than that of g-C3N4 and MoS2 alone. In addition, g-C3N4/GO (15 wt%)/MoS2 provided the highest current density (77.19 µA•cm2) for the 304 SS, which is four times that of pristine g-C3N4. All results indicate that as-prepared g-C3N4/GO (15 wt%)/MoS2 photocatalysts have produced a distinct enhancement on photocathodic protection performance. An optimum decorating amount of MoS2 onto g-C3N4 forms heterojunctions of g-C3N4/MoS2, which favor the separation of electrons and holes efficiently. Furthermore, the addition of GO further promotes the separation and transfer of photo-induced carriers.