Clean and sustainable energy is of one prime interest to current water production demands. Producing unpolluted drinking water and sustainable energy is the next big challenge to overcome. Solar steam generation has great future potentials for mankind. The need to overcome limitations of solar steam generation is in recent penchants. A highly efficient black photo-convertor nanomaterial is synthesized and functionalized to achieve 87% efficiency under one Sun (1 kW m−2) illumination. The black tin oxide (bSnO) nanomaterial was synthesized using electrocatalytic reduction approach, resulting a robust photo-convertor nanomaterial. To enhance the capabilities of water evaporation, polymerization was performed using PANI (polyaniline), and PPy (polypyrrole) referred to as bSnO@PANI and bSnO@PPy, respectively. Various physical factors as narrow bandgap, surface water ratios and localized heating are found remarkable to enhance overall efficiency. The bSnO@PANI was assessed to be at highest elevated temperature by acquiring nearly ∼82 °C in close to 100 s under one sun irradiance and nearly ∼56 °C when in contact with water body. Thus, final water evaporating rate recorded to be 2.04 kg m−2 h−1 and 1.74 kg m−2 h−1 for water and seawater, respectively. Producing drinking water from dye and sea-water are reported after solar evaporation. Achieving enormous evaporation rate can further be explored for green energy generation.