Search

A new Mg-doped Zn 0.5 Ni 0.5 Fe 2 O 4 (Mg–FZN) photocatalyst was synthesised using a simple co-precipitation-doping technique to develop a dual-function material with the ability to degrade hazardous and refractory pollutants and inactivate bacterial strains. The characterization results revealed that Mg-FZN is an n -type semiconductor with a conduction band of −0.413 eV, an average pore width of 2.32 nm, and a crystal size of 31.45 nm. The photocatalytic activity of Mg-FZN was assessed based on the degradation of 2,4,5-trichlorophenol and achieved 83.8% degradation efficiency under optimised conditions. The radical quenching results revealed that h + significantly contributed to the photodegradation process while •OH, and •O 2 − played key roles. Additionally, within 60 min, 25 mg of Mg–FZN had bactericidal effects on the bacteria E. coli and S. aureus in both the presence and absence of UV light. Mg–FZN showed H-bonding, electrostatic, and metal-contact interactions with the amino acid residues of the bacterial protein with high binding scores (−4.711 kcal/mol and −5.872 kcal/mol), according to molecular docking. [Display omitted] • Mg-doped binary metal ferrite (Mg-FZN) was synthesised via facile co-precipitation method. • Mg-FZN is an n -type semiconductor with a specific surface area of 71.8 m2/g. • 10 mg of Mg-FZN degraded 83.8% of trichlorophenol at pH 3 with a rate of 0.046 min−1. • 15 mg of Mg-FZN exhibited bactericidal effects on bacteria strains within 60 min. • The binding mechanism of bacteria protein and Mg-FZN revealed by molecular docking. [ABSTRACT FROM AUTHOR]

Removals of tetracycline and photocatalytic degradation of phenol by Fe 3 O 4 /coffee residue (MCC) were investigated. Brunauer–Emmett–Teller (BET), vibrating sample magnetometer (VSM) and Boehm titration were employed to characterize MCC. Artificial neural network (ANN) model was developed to predict the tetracycline (TC) concentration in the column effluent. Maximum tetracycline adsorption capacity of 285.6 mg/g was observed in a batch system. High removal efficiency (87%) was obtained at 3.3 mL/min flow rate, 8.0 cm bed height and 50 mg/L influent TC concentration in a column system. Complete degradation of phenol by solar-Fenton was attained at 60 min irradiation time. Total organic carbon (TOC) removal increased to 63.3% in the presence of 1.0 g/L MCC, 1.2 g/L H 2 O 2 and solar irradiation. MCC showed remarkable potential to remove antibiotics from wastewater even in the presence of heavy metal (Ni 2+ ) via magnetic separation. [ABSTRACT FROM AUTHOR]

A cost-competitive MnFe-LDO–biochar hybrid catalyst was successfully synthesized via a simple yet efficient technique for the decomposition of metronidazole (MZ). MnFe-LDO–biochar was characterized by various techniques and the results revealed that it has a bandgap of 2.85 eV, high photocurrent response of 3.8 μA cm−2 and can be separated rapidly from the bulk solution by an external magnet due to its saturation magnetization of 28.5 emu g−1. Initially, in the dark condition, 20% of MZ was removed after 30 min when 20 mg L−1 MZ solution was treated with 50 mg MnFe-LDO–biochar in the presence of 6 mM H 2 O 2. The MZ degradation increased remarkably to ∼98% upon exposure to a UV light for 60 min. Under various processes, UV/MnFe-LDO–biochar/H 2 O 2 presented high degradation rate constant of 0.226 min−1 and lowest energy consumption cost of 0.38$ at 7.56 kWh m−3 which is ∼13 times lower than the degradation of MZ by the photolytic process under similar conditions. The MZ photocatalytic decomposition trend revealed a multiprocess mechanism influenced majorly by •OH and partly by h + and •O 2 −. Note that in MnFe-LDO–biochar/UV system; 5% of MZ degradation was observed after 120 min and reached 13% after 300 min. MnFe-LDO–biochar maintained ∼88% reuse efficiency after three consecutive recycling tests. • Hybrid reusable catalyst MnFe-LDO–biochar was fabricated via co-precipitation-calcination technique. • MnFe-LDO–biochar has a bandgap of 2.85 eV and a high photocurrent response of 3.8 μA cm−2 with interconnected pores. • UV/MnFe-LDO–biochar/H 2 O 2 photodegraded ∼98% of metronidazole (20 mg L−1) in 60 min. • Degradation of antibiotic was influenced majorly by.•OH/•SO 4 − and partly by h + /•O 2 −. • Electrical energy cost is 0.38$ for achieving ∼98% treatment efficiency at 7.56 kWh m−3. [ABSTRACT FROM AUTHOR]

• Cost-competitive hybrid (MnFe-LDO–biochar) photocatalyst was successfully prepared. • MnFe-LDO–biochar has a bandgap of 2.85 eV and a high photocurrent response of 3.8 μA. • Large surface area containing mixed metal oxide oxidizing sites of MnFe-LDO–biochar improved its antibiotic degradation. • 50 mg MnFe-LDO–biochar/K 2 S 2 O 8 degraded ∼98 % tetracycline within 60 min upon exposure to a UV light. • MnFe-LDO–biochar performed sufficiently in a wide practical pH without significant leaching. A high-efficiency layered double oxide-biochar hybrid (MnFe-LDO–biochar) catalyst was successfully synthesized by the co-precipitation-calcination process and used to effectively remove tetracycline (TC) pollution. The characterization results verified that MnFe-LDO–biochar possesses a specific surface area of 524.8 m2 g−1, appropriate bandgap (2.85 eV), a high photocurrent response (3.8 μA cm–2), a saturation magnetization of 28.5 emu g−1 and a mixture of interconnected pores. 40 % of TC was removed after 30 min when 50 mL TC solution (20 mg L−1) was treated with 50 mg MnFe-LDO–biochar in the dark and reached ∼98 % degradation rate within 240 min upon exposure to a UV light. Notably, in the presence of H 2 O 2 or K 2 S 2 O 8 , the degradation rate of MnFe-LDO–biochar was shortened to 60 min with an average pseudo-first-order rate constant of 0.0445 min−1. The antibiotic removal rate of the cost-competitive MnFe-LDO–biochar surpassed several reported materials and maintained ∼80 % reuse efficiency after 3rd successive cycles. The TC photodegradation mechanism is multiprocess induced majorly by OH and SO 4 − while h+ and O 2 − contributed partly to the mineralization. This work highlights the powerful synergistic combination of layered double oxide (LDO) and biochar. [ABSTRACT FROM AUTHOR]