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Abstract Over the past few decades, enormous interest has been manifested in utilizing biomass or agricultural wastes as a renewable resource for energy and advanced material production. Despite being the utmost abundant polymer on earth, nanocellulose has drawn tremendous attention due to its intrinsic reliability and sustainability. In this study, nanocrystalline cellulose (NCC) was isolated from oil palm biomass waste i.e. oil palm empty fruit bunch (EFB) via a multistep process to testify its high capacity as a biosorbent for textile effluent contaminant remediation. Fourier transform infrared spectroscopy (FTIR) suggested that lignin, hemicellulose and other impurities had been effectively removed at different stages of preparation which was generally in agreement with ASTM chemical composition analysis. Thermogravimetric analysis with derivative thermograms (TGA-DTG) observed the extracted NCC to have the lowest weight loss throughout water evaporation region (25 °C - 100 °C), cellulose thermal degradation region (150 °C - 380 °C) and carbonic residue degradation (up to 600 °C) owing to its compact crystalline structure as evidenced from X-ray diffraction (XRD) analysis. Batch adsorption were conducted to study effect of contact time (up to 200 min), adsorbent dosage (0.005–0.05 g), pH (2–10), agitation (50–250 rpm) and adsorbate concentration (50–300 mg/L) at 30 ± 2 °C. Field emission scanning electron microscope (FESEM) observed a flower-like structure of methylene blue (MB) coating upon adsorption, following a type II adsorption isotherm which suggest an adsorption occurred on mesoporous structure. The kinetic data agreed well with pseudo-second-order model which implied the current study a chemisorption process. As adsorption capacity was highly dependent on adsorbate concentration and adsorbent dosage, 50.91 mg/g was recorded for MB solution (50 mg/L) at adsorbent dosage as low as 0.066 mg/ml; a very encouraging outcome in the recent years of cellulosic research suggesting NCC a highly promising candidate for uprising functional cellulosic soft material fabrication. Graphical abstract Image 1 Highlights • Nanocellulose with high cellulose I content and crystallinity was developed from oil palm EFB. • Characterization was made via ASTM composition analysis, FTIR, TGA-DTG, XRD, BET and FESEM technique. • Adsorption best fitted to pseudo-second-order kinetic and Langmuir isotherm model. • Electron microscope observed flower-like structure of MB dye coating upon adsorption. [ABSTRACT FROM AUTHOR]

Aerogel based on reduced graphene oxide was synthesized using supercritical methods of drying the hydrogel in isopropanol. The synthesis technique involves the deposition of iron hydroxides on graphene layers, then their reduction in supercritical isopropyl alcohol to iron oxides (Fe 3 O 4 and γ-Fe 2 O 3). Results revealed that synthesized adsorbents Graphene aerogel (GA) and GA/Fe show excellent high gravimetric methane adsorption with an achievable capacity of 2.5 g/g and 3.6 g/g, respectively, in the pressure range of 0.5–10 MPa and 298 K, which is more than seven times higher than the requirements established by the US Department of Energy for the gravimetric capacity of a porous material for methane storage. However, at high gravimetric absorption, the volume absorption was 104 m3 (STP)/m3 and 102 m3 (STP)/m3 for (GA) and (GA/Fe), respectively. It should be noted that the performance characteristics of aerogels, in general, are comparable to adsorbents of other classes. A generalized flow-chart for obtaining the graphene aerogel. [Display omitted] [ABSTRACT FROM AUTHOR]

Aerogel based on reduced graphene oxide was synthesized using supercritical methods of drying the hydrogel in isopropanol. The synthesis technique involves the deposition of iron hydroxides on graphene layers, then their reduction in supercritical isopropyl alcohol to iron oxides (Fe 3 O 4 and γ-Fe 2 O 3). Results revealed that synthesized adsorbents Graphene aerogel (GA) and GA/Fe show excellent high gravimetric methane adsorption with an achievable capacity of 2.5 g/g and 3.6 g/g, respectively, in the pressure range of 0.5–10 MPa and 298 K, which is more than seven times higher than the requirements established by the US Department of Energy for the gravimetric capacity of a porous material for methane storage. However, at high gravimetric absorption, the volume absorption was 104 m3 (STP)/m3 and 102 m3 (STP)/m3 for (GA) and (GA/Fe), respectively. It should be noted that the performance characteristics of aerogels, in general, are comparable to adsorbents of other classes. A generalized flow-chart for obtaining the graphene aerogel. [Display omitted] [ABSTRACT FROM AUTHOR]