Current work reports the first investigation on the nanocomposites of molybdenum and zinc oxide [MoO3@ZnO] synthesized via chemosynthetic and biomimetic routes. Chemosynthetic and biomimetic MoO3@ZnO nanocomposites expressed a direct band gap of 4.5 and 3.5 eV, explored via ultraviolet spectrophotometry capped with organic functional groups shown by Fourier transform infra-red spectroscopy. Polycrystalline patterns expressing average crystallite sizes of 36.9 and 22.5 nm for nano composites were revealed by X-ray diffraction. Nanocomposites expressed capsule and spherical shapes shown by field emission scanning electron micrographs with strong signals for Mo, Zn and O shown via energy dispersive X-ray spectroscopy. Raman spectroscopy revealed the successful synthesis of the MoO3@ZnO nanocomposite. Electrochemical studies included cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Redox peaks revealed the pseudo-capacitive behavior shown. EIS Nyquist plot with an arc radius pointed the existence of resistance mechanism arising from interfacial layer taking place at the electrode MoO3@ZnO nanocomposite surficial region with charge transfer resistance R-ct of 1/4 22.02 Omega. The semi-conducting and capacitive behavior of the biogenic nanocomposite makes it a future candidate for utilization in solar cells and other photovoltaic devices marked by profound sustainability, eco-friendliness, economic viability and scalability in comparison to environmentally damaging chemosynthetic solvo-thermal pathway. (c) 2020 Elsevier Ltd. All rights reserved.