The development of sustainable solutions for meeting escalating needs, such as clean energy and safe drinking water, is of the utmost importance to the modern world. Hydrogen as a fuel can be worthiest for this purpose, and further generating it from wastewater via green routes, i.e. photo/electrocatalytic splitting, can make it a sustainable solution, overcoming challenges of wastewater treatment simultaneously. In this chapter, we have discussed different materials that can be utilized as photoelectrocatalyst focusing on 2D materials for hydrogen generation from wastewater (textile, pharmaceutical, food industry, etc.). The potential catalytic properties of transition metal dichalcogenides (TMDs), transition metal oxides (TMOs), MXenes, graphene, nitrides, carbides, and their hybrids are discussed for the same. The standard diagnostic parameter for evaluating photoelectrocatalyst is photo response, incident photon to current efficiency, faradaic efficiency, and wastewater treatment in terms of percentage degradation, COD, TOC, etc., are presented and compared for 2D materials. Further, material performance in terms of the band gap, appropriately positioned valence and conduction bands, stability, economics, etc., are also compared for the wastewater systems. Last but not the least, the future outlook of the field is also presented with respect to challenges and research directions to tap this important unused energy source, i.e. wastewater.