Synthesis and properties of composite material "Mo2C — carbon fiber"

Molybdenum semicarbide Mo2C was synthesized on carbon fibers Carbopon-B-22 by the method of currentless transfer in molten NaCl-KCl-Na2MoO4-Mo salts. The electrocatalytic activity of the Mo2C/C composite material in a hydrogen peroxide solution has been investigated. It was revealed that this composite material is catalytically inactive in an H2O2 solution. The electrocatalytic activity of composite materials Mo2C/C, TaC/C, NbC/C and uncoated carbon fiber in the decomposition of hydrogen peroxide is compared. The method of cyclic voltammetry confirmed the low activity of Mo2C/C in comparison with other composites.

Synthesis of MFe2O4/CNS (M = Zn, Ni, Mn) Composites Derived from Rice Husk by the Hydrothermal-Microwave Method for Remediation of Paddy Fields

In this research work, MFe2O4/CNS was prepared using the hydrothermal–microwave method. The influence of cations (M) toward functional groups of composites and their performance in pesticide degradation were studied. Rice husk was pyrolyzed hydrothermally (200 °C, 6 h) and by microwave (800 W, 40 min). Each product was mixed with MCl2 (Zn, Ni, Mn), FeCl3, KOH, and water, and calcined (600 °C, 15 min) to obtain a composite. Characterization by XRD confirmed the MFe2O4/CNS structure. The FTIR spectra of the composites showed different band sharpness related to C-O and M-O. A mixture of dried paddy farm soil, composite, BPMC (buthylphenylmethyl carbamate) pesticide solution (0.25%), and H2O2 solution (0.15%) was kept under dark conditions for 48 h. The solution above the soil was filtered and measured with a UV-Vis spectrophotometer at 217 nm. Applications without the composite and composite–H2O2 were also conducted. The results reveal that dark BPMC degradation with the composite was 7.5 times larger than that without the composite, and 2.9 times larger than that without the composite–H2O2. There were no significantly different FTIR spectra of the soil, soil–BPMC, soil–BPMC-H2O2, and soil–BPMC-H2O2 composite and no significantly different X-ray diffractograms between the soil after drying and soil after application for pesticide degradation using the composite.

Kandungan Mikroplastik pada Sedimen di Perairan Bandengan Kabupaten Kendal

Mikroplastik adalah plastik yang berukuran kurang dari 5 mm sehingga dapat ditrasnportasikan disedimen dan memiliki dampak pada lingkungan. Penelitian ini bertujuan mengetahui bentuk dan jumlah mikroplastik di sedimen Perairan Bandengan Kabupaten Kendal. Sampel sedimen diambil pada Bulan April dan Agustus 2019 secara purposive sampling menggunakan sediment grab pada 3 stasiun berbeda, yaitu stasiun 1 (berjarak ± 9 km dari muara ke laut lepas. Stasiun 2 (berjarak ± 3 km dari muara ke laut lepas dan stasiun 3 (Muara) pada kedalaman lapisan sedimen masing-masing stasiun 2 m. Sedimen sebanyak 25 g direndam dalam 100 ml larutan ZnCl2 (972 g ZnCl2 + 1000 ml akuades) selama 24 jam. Partikel mikroplastik yang mengambang diambil lalu direndam dalam larutan H2O2 30% 50 ml selama 24 jam, kemudian disaring dengan kertas whattman nomor 42 ukuran pori 2 μm dan diamati dengan mikroskop pada perbesaraan 10x10. Keberadaan mikroplastik di Perairan Bandengan Kabupaten Kendal diduga berasal dari industri disekitar perairan aktivitas nelayan serta kegiatan masyarakat dengan bentuk mikroplastik yang ditemukan yaitu fiber, fragmen, film dan pelet. Jumlah mikroplastik pada Bulan April di stasiun 1, 2 dan 3 berturut turut adalah 271, 142 dan 107 partikel, sedangkan pada Bulan Agustus di Stasiun 1, 2 dan 3 adalah 144, 178, dan 83 partikel. Bentuk mikroplastik yang dominan bervariasi di setiap stasiun pada kedua waktu pengamatan. Pada April, bentuk mikroplastik yang dominan adalah pelet (189 partikel), sedangkan pada Agustus, jumlah terbanyak adalah pelet (186 partikel). Warna yang paling banyak adalah hitam (222 partikel). Ukuran mikroplastik terkecil adalah pelet (1,14 µm) dan terpanjang adalah fiber (214,4 µm). Microplastics are plastics that are less than 5 mm in size so that they can be transported in sediment and have an impact on the environment. This study aims to determine the shape and amount of microplastics in the sediments of Bandengan waters in Kendal Regency. Sediment samples were taken in April and August 2019 by purposive sampling using sediment grabs at 3 different stations, namely station 1 (± 9 km from the estuary to the open sea. Station 2 (± 3 km from the estuary to the high seas) and station 3 (± 3 km from the estuary to the high seas). Estuary) at a depth of 2 m of sediment layer at each station. 25 g of sediment was immersed in 100 ml of ZnCl2 solution (972 g ZnCl2 + 1000 ml distilled water) for 24 hours. Floating microplastic particles were taken and then immersed in 30% 50 ml H2O2 solution for 24 hours, then filtered with Whattman paper number 42 with a pore size of 2 μm and observed with a microscope at a magnification of 10x10.The presence of microplastics in Bandengan waters, Kendal Regency is thought to have come from industries around the waters of fishing activities as well as community activities with microplastic forms found, namely fiber, fragments , films and pellets. The number of microplastics in April at stations 1, 2 and 3 were 271, 142 and 107 particles, respectively. Shows in August at Stations 1, 2 and 3 are 144, 178, and 83 particles. The dominant form of microplastic varied at each station at the two observation times. In April, the dominant form of microplastic was pellets (189 particles), while in August, the highest number was pellets (186 particles). The most common color was black (222 particles). The smallest microplastic size was pellets (1.14 µm) and the longest was fiber (214.4 µm).

Synthesis, characterization, and photocatalytic efficiency of a new smart PdO oxide nanomaterials for using in the recycling and sustainable wastewater treatment

Nanostructured PdO materials with promising catalytic properties were successfully synthesized by the controlled thermal decomposition in air of three Pd(II) complexes containing Pd(II) ion, ofloxacin drug and amino acid. The Pd(II) complexes which were used as precursors were [Pd(OFL)(Gly)]Cl, [Pd(OFL)(Ala)]Cl, and [Pd(OFL)2]Cl2, where Gly is glycine amino acid, Ala is alanine amino acid, and OFL is ofloxacin. Structural and morphological properties of the synthesized PdO materials were obtained using FTIR, XRD, SEM, and EDX techniques. The XRD results confirm the tetragonal structure of PdO. The obtained PdO materials were tested as a catalyst for the heterogeneous degradation of H2O2 solution. The results revealed that PdO could effectively degrade H2O2. KEY WORDS: PdO, Nanoparticles, Photocatalytic efficiency, Wastewater treatment Bull. Chem. Soc. Ethiop. 2021, 35(1), 107-118. DOI: https://dx.doi.org/10.4314/bcse.v35i1.9