Engineering photocatalytic material has always been an immensely captivating prospect for tackling global energy demands and environmental pollution. Especially two-dimensional (2D) semiconductors with quasi-resistance-free lateral charge transfer pathways and tunable optoelectronic characteristics, like polymeric graphitic carbon nitride (g-C₃N₄),a metal-free semiconductor with a band gap (2.7 eV), has enormous potential as visible light-active photocatalysts and also became hot-spot in various scientific exploits. However, in photocatalysis, pristine g-C₃N₄ still suffers from a critical limitation such as limited active sites and high charge-carrier recombination. Therefore, the exploration of significant modification in g-C₃N₄ such as construction of heterojunction between g-C₃N₄ and other 2D semiconductor using green and environmentally friendly methods is required to address the related issues of particular importance. Meanwhile, heterogeneous photocatalysis is regarded as one of the most promising choices in the search for long-lasting and highly effective solutions for environmental remediation. In addition, constructing heterojunction between 2D g-C₃N₄ nanosheets and other 2D transition metal dichalcogenide semiconductors, such as tungsten disulfide (WS₂), which can help to further increase the efficient separation of the photogenerated charge carriers. As a result, photon absorption in the electromagnetic spectrum's visible region is greatly improved. However, their practical use is severely constrained by the difficulties associated with recovering such powdery 2D material-based composite photocatalysts from the reaction solution. Therefore, the transition from 2D material to 3D material based composite photocatalyst paves a way for the development in this dynamic research field.