The Preparation Of Graphene-Decorated Porous Ceramics Composite And Its Application In Water Purification

Porous ceramics(such as activated alumina(AA)) is a common adsorbent material in water purification. Its purifying capacity can be greatly improved through modification of porous ceramics. In the first part, a facile method has been established to prepare a graphene-decorated porous ceramic(GDPC) material. Citric acid(CA) was absorbed into the inner surface of the porous ceramics and transformed to graphene via sintering. The as-prepared material showed excellent adsorption capacity for chromium(Cr(VI)) over a wide range of pH(2 to 10) compared with the blank sample. The maximum uptake capacity for Cr(VI) exceed 699.43 mg g-1. UV and ICP-OES tests indicated that chromium ions in aqueous solution were completely removed via the GDPC. Thus the GDPC could be a potential adsorbent for the environmental cleanup, especially for the chromium-contained wastewater disposal.In the second part, the resulted graphene-decorated AA was used to remove methylene blue(MB) in aqueous solution. Study showed that the performance of the as-prepared material for the removal of MB was significantly improved. It was demonstrated that the adsorption capacity of the modified porous ceramics was higher than the original AA and activated carbon. Experimental data analysis indicated that Freundlich isotherm model was more suitable to describe the adsorption behavior than Langmuir model. In addition, the kinetic studies suggested the pseudo-second-order model for the adsorption process. It is expected that this low-cost adsorbent could be valuable for disposal of wastewater that contains dyes and other organic components.In the third part, two kinds of coal(Anthracite and bituminous coal) were purified by boll milling, ultrasound and ectraction. The as-prepared coal was characterized by XRD, SEM, IR, XPS, Raman, etc. The purified coal were dispersed in organic solvent by ultrasound and the dispersion was got by centrifuge and was characterized by TEM, HRTEM. The resulted dispersion was mixed with specific shape polyurethane(PU) foam. After 30 minutes of ultrasound, coal/PU composite was got. Compared with pure PU or the composite without ultrasound, the coal/PU composite can greatly increase its adsorption capacity of oil. Moreover, the electric conductivity of PU was strongly improved after immobilized with coal. This may be one of the most facile and low-cost method to prepare coal/PU composite and the composite also has the potential to be used in wastewater treatment.