A review on emerging homojunction photocatalysts with impressive performances for wastewater detoxification

Heterogeneous photocatalysis, as an energy-saving technology, is a fascinating strategy to tackle environmental issues and energy shortages. The efficacy of these processes is severely relevant to the suppression of charges recombination, which hinders the widespread utilization of these processes. The segregation of charges from fast recombination can be considerably improved by the formation of heterojunction among the components of photocatalysts. Nevertheless, the formed heterojunction between different semiconductors diminishes the continuity of the charges carriers transfer amongst the semiconductors. Moreover, the construction of heterojunctions significantly relies on matching of band structures of the desired semiconductors. Hopefully, homojunction construction between different exposing facets, morphologies, and crystal phases of a single semiconductor is a feasible strategy for impressively suppression of charges from recombination. In comparison with the heterojunction photocatalysts, the almost identical components in both sides of the junction area provide not only the incredibly matched lattice, but also the integrity of bonding between the counterparts, which facilitates the charge migration within the photocatalyst. Furthermore, the established built-in electric field in the junction regions could enforce the charge carriers for efficiently separation and transfer within these photocatalysts. Herein, we reviewed the latest researches about the emerging homojunction photocatalysts and their application in the degradation of various wastewater pollutants. The present review intends to stimulate the research communities to focus on this kind of photocatalysts, as emerging materials, with the impressive performances in the photocatalytic processes.