Amid the escalating global environmental concerns and energy demands, the synergistic remediation of these challenges through sustainable methodologies is paramount. Photocatalysis, a pivotal green technology, holds promise for energy evolution and pollutant degradation. We present a simple strategy for synthesizing CdS, MoS₂, and CdS/MoS₂ heterostructures via a cost-effective solution-based approach. The resultant materials exhibit hierarchical nanoarchitectures- nanoparticles, nanorods, and nanoflakes- controllable by solvent selection, such as water, ethylene glycol, and ethylenediamine, using L-cysteine, a natural source of sulfur, and demonstrate their photocatalytic performances. Employing density functional theory simulations, we corroborate experimental findings, unveiling structural evolution, band gap variation, and enhanced photocatalytic and photoresponsive properties. The CdS/MoS₂ heterostructure demonstrates remarkable charge transfer and photoconductivity, stemming from van der Waals interactions and charge migration. This synergistic effect of charge transfers and lattice mismatch of these hybrid nanostructures  manifests a substantially narrowed band gap, outperforming pristine counterparts, and substantiates exceptional photocatalytic and light-sensing performance. Our study advances morphology-driven photocatalysis, offering novel insights into green energy conversion.