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[Display omitted] In recent years, the research on intrinsically safe aqueous zinc-ion batteries (AZIBs) has gained significant attention. However, the commercialization of AZIBs is hindered because of the formation of dendrites in them and undesired hydrogen evolution reaction (HER) at their anode. MXene is a promising two-dimensional material that can inhibit dendrite growth and undesired HER at the anode when used as a protective layer for the anode in AZIBs. MXene's surface functional groups play a crucial role in this protective function. However, the working mechanisms of these surface functional groups have not been thoroughly understood. Based on first-principles calculations and molecular dynamics simulation, we investigated the mechanisms of MXene with nine surface functional groups, including oxygen and halogen elements, as an anode protection layer. We checked their structural stability, electronic structure, adsorption energy, HER reaction free energy, Zn2+ diffusion energy barriers, coordination number of Zn2+- H 2 O and diffusion coefficients of Zn2+. The MXene species with -S and -O functional groups exhibit good electrical conductivity and greatly adsorb Zn2+. Conversely, MXene species with halogen-functional groups significantly inhibit HER reactions. MXene materials with -Se functional group have the best desolvation effect (ΔCN = 0.31), while those with -I end group have the fastest ability to diffuse zinc ion. This research provides a theoretical guidance for the design of MXene based anode protection layers, which can help to develop dendrite-free and low side-reaction AZIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Tricobalt tetroxide (Co 3 O 4) has been developed as a promising photocatalyst material for various applications. Several reports have been published on the self-modification of Co 3 O 4 to achieve optimal photocatalytic performance. The pristine Co 3 O 4 alone is inadequate for photocatalysis due to the rapid recombination process of photogenerated (PG) charge carriers. The modification of Co 3 O 4 can be extended through the introduction of doping elements, incorporation of supporting materials, surface functionalization, metal loading, and combination with other photocatalysts. The addition of doping elements and support materials may enhance the photocatalysis process, although these modifications have a slight effect on decreasing the recombination process of PG charge carriers. On the other hand, combining Co 3 O 4 with other semiconductors results in a different PG charge carrier mechanism, leading to a decrease in the recombination process and an increase in photocatalytic activity. Therefore, this work discusses recent modifications of Co 3 O 4 and their effects on its photocatalytic performance. Additionally, the modification effects, such as enhanced surface area, generation of oxygen vacancies, tuning the band gap, and formation of heterojunctions, are reviewed to demonstrate the feasibility of separating PG charge carriers. Finally, the formation and mechanism of these modification effects are also reviewed based on theoretical and experimental approaches to validate their formation and the transfer process of charge carriers. [ABSTRACT FROM AUTHOR]