Effects of Co3O4 modified with MoS2 on microbial fuel cells performance.

In this study, Co3O4@MoS2 is prepared as anodic catalytic material for microbial fuel cells (MFCs). As the mass fraction of MoS2 is 20%, the best performance of Co3O4@MoS2 composite catalytic material is achieved, and the addition of MoS2 enhances both the electrical conductivity and catalytic performance of the composite catalyst. Through the structural characterization of Co3O4@MoS2 composite catalytic material, nanorod-like Co3O4 and lamellar MoS2 interweaved and stacked each other, and the agglomeration of Co3O4 is weakened. Among the four groups of single-chamber MFCs constructed, the Co3O4@MoS2-MFC shows the best power production performance with a maximum stable output voltage of to 539 mV and a maximum power density of up to 2221 mW/m2. Additionally, the ammonia nitrogen removal rate of the MFCs loaded with catalysts is enhanced by about 10% compared with the blank carbon cloth MFC. Overall, the findings suggest that Co3O4@MoS2 composite catalysts can significantly improve the performance of MFCs, making them more effective for both energy production and wastewater treatment.

Highly efficient Ni-Mo-P composite rare earth elements electrode as electrocatalytic cathode for oil-based drill sludge treatment.

It is considered an effective strategy to improve electrochemical performance that introducing rare elements into metal catalysts, which would provide abundant electrochemical active sites and be a benefit for redox reactions. A new Ni-Mo-P composite electrode material modified with rare earth elements (light rare earth Nd and heavy rare earth Yb) was prepared, evaluating the current density of direct current electrodeposition, the doping ratio of Yb and Nd, and the cyclic voltammetry deposition (CVD) cycle numbers on electrode structure and electrochemical performance. The results showed that the electrode has the most obvious amorphous state, the lowest hydrogen evolution overpotential (41.5 mV vs Ag/AgCl) and charge transfer resistance (15.74 Ω/cm2), and remarkable stability when the molar ratio of Yb and Nd was 8:2 and the 20 cycle numbers under the CVD condition. The electrochemical performance and characterization of the electrode showed that there was a good synergistic effect between rare earth elements (Yb, Nd) and Ni-Mo-P alloys. The oil-based drill sludge (OBDS) treatment indicated that the organic matter content is significantly reduced by using the above-modified electrode as the cathode, and the COD and petroleum removal rate can reach up to 85.4 ± 1.2% and 66.2 ± 5.9%. The effect of degradation for aliphatic hydrocarbon was better than aromatic hydrocarbons and no other intermediates are produced during the degradation, which may eventually mineralize the organic matter. This research provided technical support for the preparation of new Ni-Mo-P electrodes modified with rare earth elements and confirmed that electrocatalytic technology was a suitable method for OBDS treatment.