Organic template-based ZnO embedded Mn₃O₄ nanoparticles: synthesis and evaluation of their electrochemical properties towards clean energy generation

Abstract

To deal with fossil fuel depletion and the rise in global temperatures caused by fossil fuels, cheap and abundant materials are required, in order to fulfill energy demand by developing high-performance fuel cells and electrocatalysts. In this work, a natural organic agent has been used to synthesize nanostructured ZnO/Mn 3 O 4 with high surface area and enhanced electrocatalytic performance. Upon preannealing treatment, mixed metal oxide precipitates are formed due to the complex formation between a metal oxide and organic extract. The thermally annealed mixed oxide ZnO/Mn 3 O 4 was characterized by XRD diffractometer, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). Gas chromatography-mass spectrometry (GC-MS) identified methyldecylamine as a major stabilizing agent of the synthesized nanomaterial. Using a Tauc plot, the calculated band energy for the synthesized ZnO/Mn 3 O 4 mixed metal oxide was 1.65 eV.Moreover, we have demonstrated the effects of incorporated organic compounds on the surface chemistry, morphology and electrochemical behavior of ZnO/Mn 3 O 4 . The phyto-functionalized ZnO/ Mn 3 O 4 was deposited on Ni-foam for electrocatalytic studies. The fabricated electrode revealed good performance with low over-potential and Tafel slope, suggesting it to be suitable as a potential catalyst for water splitting application, in particular for the oxygen evolution reaction (OER). The overall findings of the current study provide a cost-effective and efficient organic template for functionalization and sustainable fabrication of ZnO/Mn 3 O 4 nanomaterial for application as an electrocatalyst.

Recent advances in graphene-based materials for dye-sensitized solar cell fabrication

“…The excited dye molecule is oxidized without any time delay, as illustrated in eqn (2), where S + is the oxidized dye molecule. Hence, an electron is injected into the conduction band of the semiconducting oxide lm, where it freely ows to the external circuit via a transparent conducting electrode: [35][36][37] S* / S + + e À…”

“…Renewable energy sources, such as wind, geothermal, biomass and solar energy, have gained tremendous research interest in recent years, to address up-coming global issues, particularly the depletion of conventional energy resources, e.g., fossil fuels, due to the ever-increasing energy demand, coupled with greenhouse gas emissions that lead to global warming and climate change. [1][2][3][4] Among the renewable energy sources, solar energy is more appealing owing to its natural abundance and environmentally friendly benet, since it entails the provision of clean energy harvested from the Sun. 5 In this regard, recent work has been focussing on the fabrication of third generation photovoltaic devices, such as organic solar cells (OSCs), 6,7 dye-sensitized solar cells (DSSCs), 8,9 and perovskite solar cells, 10,11 in an attempt to overcome the drawbacks of the rst and second generation solar cells.…”

Green synthesis of doped Co3O4 nanocatalysts using organic template for fast azo dye degradation from aqueous environment

“…The identified functional groups have been reported as stabilizing agents of synthesized nanomaterials. 1,2,12, [30][31][32][33][34] Consequently, FTIR analysis showed stabilization of Co 3 O 4 by phytochemicals having hydrocarbon and amine functional groups while Co 3 O 4 :PdO/Pd and Co 3 O 4 :NiO were incorporated with phenolic compounds as stabilizing agents.…”

“…GC-MS data revealed benzeneethanol, benzeneethanamine and cyclobutanol as major organic constituents of A. pindrow, indicating the presence of phenols and flavonoids in A. pindrow. These phytochemicals have been identified as reducing and stabilizing agents in the synthesis of nanomaterials by Rolim et al, 30 Hussain et al, 31 Zahra et al, 32 Jaffri and Khuram 33 and Zahra et al 34 Considering the potential of bio-entities in fabrication of eco-friendly nanomaterials, the study presented here focused on the investigation of the phytosynthesis of Co 3 O 4 , Co 3 O 4 :NiO and Co 3 O 4 :PdO/Pd nanomaterials using A. pindrow leaf extract, which were then employed in the degradation of MO in the presence of solar light as well under ambient dark conditions. The bioactive compound-based synthesis led to incorporation of carbon and oxygen functional groups in the synthesized nanomaterials which considerably enhanced their catalytic activity towards degradation of MO.…”

“…pindrow . These phytochemicals have been identified as reducing and stabilizing agents in the synthesis of nanomaterials by Rolim et al ., 30 Hussain et al ., 31 Zahra et al ., 32 Jaffri and Khuram 33 and Zahra et al 34 . Considering the potential of bio‐entities in fabrication of eco‐friendly nanomaterials, the study presented here focused on the investigation of the phytosynthesis of Co 3 O 4 , Co 3 O 4 :NiO and Co 3 O 4 :PdO/Pd nanomaterials using A .…”