How assembly matters to catalysis and thermal conductivity mediated by CuO nanoparticles

CuO nanostructures (NSs) of different morphologies were prepared, applied as catalysts for the pyrolysis of sugarcane bagasse (PSCB), and applied for thermally-conductive nanofluids. Both size and shape of the prepared NSs ranged from 5 to 1000 nm, and from nanodots (NDs) to spindle nano-aggregates (NAs), respectively. The catalytic activity of these NSs towards the PSCB was followed up by thermogravimetric analysis (TGA), where they increased the percentage of total weight loss, and lowered the decomposition temperatures of PSCB. The Coats-Redfern kinetic model showed a decline in activation energy by 57 and 9-43 kJ mol^-1 for NDs and NAs, respectively. Colloidal dispersions of CuO NDs and NAs in monoethylene glycol (MEG) were prepared with volume fractions ([Formula: see text]) of 0.01-0.04%, where thermal conductivity improved with increasing [Formula: see text]. At all values of [Formula: see text], the best enhancements were exerted by NDs. The nature of assembly impacted the catalyzed PSCB and the thermal conductivity of MEG. This behavior depends to a large extent on the NAs that expose a different fraction of crystal facets of different reactivities and surface areas, not on the constituent nanorods (NRs).