A morphological decoration of g-C3N4/ZrO2 heterojunctions as a visible light activated photocatalyst for degradation of various organic pollutants

Rational decoration of heterojunctions with photocatalytic activity under visible light has received tremendous attentions in the last decade. In particular, fine tuning the morphologies of the components of heterojunction is of great importance that can determine the efficiency of the designed photocatalyst. In this work, various graphitic carbon nitride (g-C3N4)/zirconium dioxide (ZrO2) heterojunctions were successfully synthesized via a solution mixing-calcination method using different morphologies of g-C3N4 (nanosheet and particle) and ZrO2 (nanosphere, nanorod, and nanosheet). The properties of as-designed heterojunction photocatalysts were characterized by XRD, TGA, FTIR, TEM, AFM, XPS, BET, DRS, PL, EIS, PR, and HPLC. All the designed heterojunctions showed weaker photoluminescence compared to each of components, indicating the efficient charge transfer between g-C3N4 and ZrO2, and delayed electron-hole pairs recombination process. Among the six designed heterojunctions, the highest photocatalytic activity was observed in the 2D/2D heterojunction with efficient •O2- production, which was due to higher surface area, good integration of nanosheets morphologies, existence of abundant high-rate charge transfer nanochannels and better separation efficiency of electron-hole pairs in this heterojunction. This research indicates that right selection of morphology of the nanomaterials for designing photocatalysts plays an important role in realizing efficient heterojunctions nanomaterials.