Industrial molasses waste in the performant synthesis of few-layer graphene and its Au/Ag nanoparticles nanocomposites. Photocatalytic and supercapacitance applications

In view of clean environment, the industry needs to address multiple demands at different levels of production and processes via the sustainable approach including recycling or smart use of produced waste. On the other hand, a development and success of green energy requires the crucial materials synthesized via efficient, sustainable methodology. Herein, the green, simple, easily scalable, fast, and highly efficient synthesis of few-layer graphene (FLG) and its composites with Au and Ag nanoparticles using a waste is presented. The FLG synthesis based on the exfoliation of graphite runs in water in the presence of industrial co-product, molasses, which next also shows performant reductive properties during Ag and Au NPs formation. The decreased size of NPs deposited on FLG indicates the synergetic effect of molasses and FLG, exhibiting the add role of FLG/molasses as metal stabilizer species. The NPs/FLG composites are efficient photocatalysts of bisphenol (BisA) degradation in the presence of peroxy-monosulfate (PMS) activator. The Au/FLG (PVDF) and Ag/FLG (PVDF) based electrodes reveal as well relatively high gravimetric capacitance, 205 Fg-1 and 729 Fg-1. The presented approach is much worthy to be further applied in the synthesis of other layered materials as well as other non-noble supported metallic systems. [Display omitted] •Molasses- a waste as performant surfactant in sustainable synthesis of graphene.•Molasses as efficient reductive agent in metal NPs formation.•High dispersion of graphene-supported Ag/Au due to the graphene-molasses synergy.•Nanocomposites as performant photocatalysts in degradation of bisphenol A.•Ag /graphene superior photocatalyst and supercapacitor electrode than Au/graphene.