Bismuth-based nanocomposites (BiNCs) have considered as interesting materials for applications in the fields of electrochemistry and optoelectronics, among others, due to their structural flexibility, high stability and facile manufacturing process. Their unique photo-oxidation properties are of particular interest in water splitting and pollutant degradation. The present review concern on the recent advances in architecting and morphology engineering bismuth-based heterojunction nanocomposites including bismuth-vanadate (BiVO${}_4$), bismuth-tungstate (Bi${}_2$WO${}_6$), bismuth-molybdate (Bi${}_2$MoO${}_6$), and bismuth-chalcogenides (Bi${}_2$A${}_3$; A = O, S, Se, Te), leading to enhanced efficiency of bismuthal nanocomposites through heterojunction assembly. As higher proficiency encourages environmental friendlier production, sustainable nanocomposites production approaches are highly needed in the scope of the circular economy paradigms. Thus, co-precipitation method and hydrothermal synthesis are discussed in detail due to their size selectivity, morphological variability, and reliability. This study paves the way toward the synthesis of more effective bismuthal nanocomposites with lower environmental impact. In addition, pollutants and biological components sensing capabilities of carbon, graphene and biopolymer-based BiNCs are discussed, signifying their role in environmental monitoring of heavy metals. Thus, the present review highlights the production of improved nanocomposites for photocatalysis and heavy metal sensors which are cost effective, reliable, reusable and efficient.