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Low breakdown electric field ZnO–Bi2O3–TiO2–Co2O3–MnO2 (ZBTCM) varistor ceramics doped with various amounts of B2O3 were prepared by the solid-state reactions. The sintering temperature was 900 °C, lower than the melting point of pure silver. The microstructural features and electrical properties were investigated by XRD, SEM and a capacitance meter. The results show that B2O3 is not only a sintering additive, but also an electrical property improver. ZBTCM based varistors with breakdown field of 131.25 V/mm, nonlinear coefficient (α) of 39.13 and leakage current density (JL) lower than 2.5 µA/mm2 were obtained by doping 1 wt% B2O3 sintered at 900 °C. [ABSTRACT FROM AUTHOR]

LaMnO3 with perovskite structure is a SCR de-NOx catalyst with good performance at low temperatures. In this paper, the SCR reaction process on the 010 surface of LaMnO3 catalyst was studied by DFT method, to guide the development of catalysts and their effective application. The results obtained through research indicate that both E-R and L-H mechanisms exist on the catalyst surface. The NH3 molecule can be absorbed on L acid and then oxidized by lattice oxygen to form NH2. Then, NH2 can react with the NO molecule to form NH2NO and decompose to N2 and H2O. The NH3 can also be absorbed with hydroxyl to form NH4+, it can also react with NO to form NH2NO and then decompose. The NH4+ also can react with NO3− which is formed by NO oxidized when O2 is present, to participate in the rapid SCR process. [ABSTRACT FROM AUTHOR]

Ceramic membranes based on naturally available materials are cost-effective and environmentally friendly alternatives to substitute Nafion™ 117 as separator in bioelectrochemical systems (BESs). In this study, copolymerization doped marine biomass-based (Ostrea gigas tnunb shell, OGTS; Sea sand, SS) ceramic membrane separators (CMSs) modified by Cu/Fe are synthesized by sintering. Modified CMSs exhibit superior chemical properties of acid and alkali resistance and thermodynamic stability. For CMS-ASO-Cu (CMS-Al 2 O 3 /SS/OGTS/Cu), Oxygen diffusion coefficient of 3.41 × 10−6 cm s−1 is 1.88 times higher than that of CMS-ASO-Fe (CMS-Al 2 O 3 /SS/OGTS/Fe). Proton transfer numbers of CMS-ASO-Cu is up to 0.62. Maximum power density 53.21 mW m−2 and current density 408.62 mA m−2 are achieved from CMS-ASO-Cu assisted BES, along with organic removal performance (COD >80%, NH 4 +-N > 80%, TP > 92%). Regeneration and antibacterial properties of the CMSs are confirmed by low-temperature sintering method and inhibition zone assay, ensuring the long-term, efficient and sustainable function of the C-BES. [Display omitted] • Copolymerization doped marine biowastes based ceramic membrane was synthesized. • Oxygen diffusion coefficient of CMS-ASO-Cu was 1.88 times of CMS-ASO-Fe. • Proton transfer numbers of CMS-ASO-Cu was up to 0.62. • Sustainable self-energy generation and organic removal were obtained in C-BES. • CMSs exhibited cyclic regeneration and antibacterial properties. [ABSTRACT FROM AUTHOR]

In this study, a novel pre-synthesized Bi–Sb–O phase was produced and doped into the ZnO– Bi 2 O 3 – Co 2 O 3 – MnO 2 (ZBCM)- based varistor to make an improvement in nonlinear coefficient (α) and a decrease in breakdown voltage (E 1mA). Results showed that the ZBCM- Bi–Sb–O ceramics can be well sintered with high sintering density above 0.98 of the ZnO theoretical density at a low sintering temperature of 900 °C. A large average grain size (d) of 6.89 μm was obtained in the ZBCM – 3 wt% Bi–Sb–O varistor, which leads to a low E 1mA of 235.0 V/mm. At the same time, the α increases to 53.0 due to the improved barrier height (ϕ b) of 1.85 eV. Furthermore, the lowest dielectric loss (tanδ) at low frequency as well as the increased grain resistance (R g) made the smallest leakage current density (I L) of 0.005 μA mm−2 in the same Bi–Sb–O doping content. Besides, a considerable low E 1mA of 168.91 V/mm with a mildly α of 37.4 was obtained in the ZBCM– 1 wt% Bi–Sb–O varistor. Hopefully, this novel research provided a new strategy to prepare low-voltage ZnO– Bi 2 O 3 - based varistors at low sintering temperature. [ABSTRACT FROM AUTHOR]