Vol.:(0123456789) Biomass Conversion and Biorefinery https://doi.org/10.1007/s13399-023-05247-w ORIGINAL ARTICLE Experimental and simulation studies on dye‑sensitized solar energy conversion using plasmonic ZnSnO 3 /Ag photoanodes functionalized with biomolecules M. Ani Melfa Roji 1  · P. Ram Kumar 2  · G. Jiji 3  · T. Ajith Bosco Raj 1 Received: 21 September 2023 / Revised: 15 December 2023 / Accepted: 19 December 2023 © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024 Abstract A novel approach for modifying zinc stannate nanomaterials involves using a bio-extract derived from the leaves of Hibiscus rosa-sinensis. Ag nanomaterial and biomolecule sensitization was conducted in a single pot. The composite materials of Ag and biomolecules were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis to determine their structural aspects. Based on the PXRD results, it was determined that the composites exhibit a face-centered cubic structure. The observed frequencies of C − H and Sn − O stretching in the FT-IR spectra indicate the existence of biomolecules within the composite material. Furthermore, the X-ray photoelectron spectroscopy findings validate the coordination of zinc and tin within the zinc stannate compound with biomolecules while indicating silver’s presence on the surface. Scanning electron microscopy and transmission electron microscopy techniques have revealed the material’s porous characteristics and reduction in size of the zinc stannate particles. In addition, the results demonstrated the spherical morphology of the silver particles that have undergone doping. Surface agglomeration and opti- cal characteristics were investigated using UV–Vis spectroscopy. The observed phenomenon exhibits pronounced particle agglomeration resulting from biomolecules on the surface. In addition, the emergence of an additional absorption band at approximately 453 nm can be attributed to silver’s surface plasmon resonance effect. The obtained J–V curve for all samples demonstrates the observed enhancements, resulting from incorporating Ag and biomolecules. The enhancements observed in the simulation results were further confirmed through the validation process, which demonstrated the extended absorption and surface plasmon resonance effect. Keywords Biotreatment · Bioenergy conversion · Dye-sensitized solar cells · Semiconductor · Zinc stannate 1 Introduction In recent years, there has been a notable surge of interest in renewable energy, particularly in efficient and sustain- able energy conversion technologies [1–3]. Among these technologies, photovoltaics have emerged as a prominent contender [4]. Pursuing innovative materials and methodolo- gies that augment solar cells’ efficacy and economic viability has prompted scientists to investigate diverse approaches, including using plasmonic nanocomposites [5–8]. The com- posites above, consisting of semiconducting oxides and plas- monic metals, demonstrate distinctive optical characteristics that can greatly augment the absorption of light and the gen- eration of charge carriers within photovoltaic devices [9, 10]. Plasmonic dye-sensitized solar cells are an advanced technological development in photovoltaics. These cells combine the principles of plasmonics and dye sensitization * P. Ram Kumar dr.ramchem93@gmail.com * T. Ajith Bosco Raj ajithboscoraj@gmail.com M. Ani Melfa Roji animelfarojimd@gmail.com 1 Department of Electronics and Communication Engineering, PSN College of Engineering and Technology, Melathediyoor, Tirunelveli 627 152, Tamil Nadu, India 2 Department of Chemistry, Thiagarajar College of Engineering, Madurai, Tamil Nadu 625015, India 3 Department of Electronics and Communication Engineering, Lord Jagannath College of Engineering and Technology, Nagercoil, Kanyakumari 629 402, India