This work focuses on developing a new flow-circulation system for simultaneous detection and degradation of oxytetracycline (OTC) in fish farm wastewater to address a need for antibiotic abatement in wastewater treatment. Polyvinyl pyrrolidone capped bismuth oxybromide assembled with a reduced graphene oxide (PVP-BiOBr@rGO) photocatalyst was solvothermally synthesized and characterized. The prepared photocatalyst exhibited a morphological flower-like structure with a high surface area, 47.59 m2 g-1. Its band gap energy was 2.93 eV. A ternary PVP-BiOBr@rGO composite showed lower charge recombination than its pure form. PVP-BiOBr@rGO was filled inside a catalyst column of a flow system, with a spectrophotometer at the column end. Wastewater was continuously transported through the column and OTC spectrophotometrically examined during its degradation. The wastewater was recirculated until the OTC concentration was minimized. This system achieved 90.3% degradation of OTC within 180 min. The catalyst column could be regenerated for 2 cycles. The proposed flow system offers the advantages of ease of use, inline operation, and real-time sensing. This highlights a potential for real-world sustainable wastewater treatment applications.

The Ca12Al14O33 ceramic (C12A7) and reduced graphene oxide (rGO) composite which an ultra-high amount (i.e., 40, 50, 60, and 70 wt%) of rGO (ultra-high amount C12A7/rGO composite) were synthesized by a solid-state reaction process. After the hydraulic press, the heat treatment in the temperature range of 773 K under the argon environment had been performed with the composite pellets for 30 min. XRD results of the C12A7 and all the ultra-high amount C12A7/rGO composites indicated a pure phase of C12A7 ceramic. Raman spectra confirmed the existence of rGO content in all the ultra-high amount C12A7/rGO composites. Raman peaks also suggested reduction of the free O 2 2 - and O 2 - ions from the framework of the ultra-high amount C12A7/rGO composites. SEM image presented the homogeneous grain boundary interface after the heat treatment at 773 K of the C12A7 wrapped by the rGO sheet, the agglomerated rGO sheet, and the rough interface stack of rGO sheets. UV-VIS spectroscopy presented the absorption behavior, direct energy gap, and indirect energy gap modifications of the ultra-high amount C12A7/rGO composites. Electrical conductivity of the ultra-high amount C12A7/rGO composites illustrated larger than 108 times improvement with temperature independence. Range of -5 to -17 μ V / K , temperature dependence, and increased with rGO content increasing Seebeck coefficient were reported. Thermal conductivity of the ultra-high amount C12A7/rGO composites was increased with the rGO content increasing. Both the Power factor (PF) and the figure of merit (ZT) of the ultra-high amount C12A7/rGO composites were temperature dependent and were increased with the rGO content increasing, within the range of 0.4 μ W / m . K 2 of PF and the range of 3 x 10 - 4 of ZT, respectively. These experimental results verified grain boundary, modified energy band, electrical transport properties and thermoelectric properties of C12A7/rGO composites loading with ultra-high content rGO.

Three-dimensional porous graphene (3D-PG) has attracted much attention due to its excellent electrochemical performance. Chemical reduction is one of common methods for preparing porous graphene. In order to develop a green and facile method for preparing three-dimensional porous graphene, in this paper, 3D-PG was fabricated by reduction of graphene oxide (GO) with ascorbic acid (AA) as reductant in hydrothermal condition based on non-toxic, non-flammable and mild reducing performance of ascorbic acid. It was found that the size and distribution of pores could be controlled by the reduction time and the concentration of AA in the solution. The pore sizes in R0, R1 and R2 were in the range of 0.5-1 μm, 1-1.5 μm, and 1.5-3 μm, respectively. It was found that the average pore size and volume increased along with the amount of reductants. Under optimal conditions - a reaction time of 20 h and a ratio of GO to AA=1 : 1 - the CV area of the so-obtained sample R1-20 at 100 mV was 0.06 and the specific capacitance of the 3D-PG electrode reaches 153.5 F ⋅ g-1 , which is suitable for use in supercapacitors.

The Pristine Mayenite Ca12Al14O33 (C12A7) Cement was simply synthesized by using solid-state reaction. The C12A7 and Graphene Oxide (GO) composites (C12A7_GO-x) with various contents of the GO suspension loading (x = 0 wt%, 1 wt%, 2 wt%, 3 wt%, and 4 wt%) were directly prepared by mixing the C12A7 and GO. X-ray diffraction results of pristine C12A7 and all C12A7_GO composites indicated a pure phase corresponding to the standard of C12A7 cement. Raman spectroscopy confirmed the existence of GO in all C12A7_GO samples. Scanning Electron Microscopy (SEM) showed the micrometer grain sizes and the occurrence of grain boundary interfaces for GO incorporation in all C12A7_GO samples. UV-Vis spectroscopy revealed the absorption value of all C12A7_GO samples and red shift near longer wavelengths when increasing the GO concentrations. The dielectric constant of C12A7_GO composites can be explained by the high density of free electron charges for the interfacial polarization on the GO surface. The maximum specific capacitance of C12A7_GO-4 electrode of 21.514 at a current density of 0.2 A g-1 can be attributed to the increase in the electrochemically active surface area for the formation of the electrical double layer capacitors behavior and the effects of high surface area GO connections. Also, the mechanical properties exhibited an increase in Vickers indenter hardness (HV) values with increasing GO contents. The highest HV value was 117.8 HV/2 kg at the C12A7_GO-4 sample. These results showed that the composite materials of the pristine C12A7 cement with GO were highly efficient. All in all, the GO material contained a high potential for enhancing low-cost cement materials in multifunctional properties such as optical, dielectric, electrochemical, and mechanical properties.