In-situ oxidation of CoOOH decorated on P25 heterostructure as the co-catalyst for enhanced photodegradation of organic pollutants

Surface modification of nanoscale titanium dioxide (P25) for photocatalysts can improve carrier separation efficiency by constructing heterojunction structures and reduce reaction energy barriers by introducing co-catalysts. This study describes the successful deposition of CoOOH particles on the P25 surface using solvent-based and in-situ oxidation methods, resulting in a type II P25-CoOOH heterostructure. The photocurrent of P25-CoOOH exhibited a 630 % increase compared to pure P25, while showing a reduced surface potential barrier of 2.21 eV. Density functional theory (DFT) simulations demonstrated that the work function of the CoOOH (001) surface (Φ = 6.639 eV) is significantly lower than that of P25 (101) (Φ = 7.238 eV). Photoluminescence (PL) spectra and active species trapping experiments demonstrated a slower rate of electron and hole recombination in P25-CoOOH compared to pure P25, which effectively reduces electron-hole pair recombination and significantly enhances its photocatalytic activity for degrading methylene blue (MB) by 2.07 times that of P25. These findings suggest that CoOOH not only forms a heterojunction with P25 to improve carrier separation efficiency but also serves as a co-catalyst, increasing the number of active sites on the surface.