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Developing metal-free carbon electrocatalysts with atomically precise structures of hetero-doping is crucial for inventing reliable alternatives to precious metal-based catalysts. Our study reveals that the optimal active site is the edge-exposed N-neighbored carbon site in a chained N- C -C-S structure. Carbon material with N- C -C-S functional doping is controllably synthesized through polymer dehalogenation and heteroatom doping with thiomorpholine at room temperature. The resulting N/S-co-doped carbon with N- C -C-S functionalization, named N-C 2 -S, exhibits excellent ORR performance compared to other types of N, S-co-doped carbon, and commercial Pt/C. Typically, the N-C 2 -S sample shows the earliest onset potential of 0.96 V and a high half-wave potential of 0.85 V for promoting ORR. Assembled into an Al-air battery, The N-C 2 -S delivers an exceptional open-circuit voltage of 1.95 V and a large specific power of 128.1 mW cm 2. The synthesis strategy developed in this work can potentially open up precise functionalization of synthetic carbons with heteroatoms. [Display omitted] • The C site near the N in N-C-C-S is identified as highly active for oxygen reduction. • Different types of N, S-co-doped carbon are obtained via dehalogenation of PVDC. • N-C-C-S doping is realized via dehalogenation coupling reaction with thiomorpholine. • The N-C 2 -S sample exhibits exceptionally good oxygen reduction reaction performance. • The N-C 2 -S-assembled Al-air battery delivers high cell voltages and large powers. [ABSTRACT FROM AUTHOR]

The remote and non-invasive optical thermometer exploiting fluorescence intensity ratio technology is of great importance in various intelligent optoelectronic sensors. Dual-emitting YNbO 4 :Bi3+, Eu3+ phosphor is synthesized and investigated for the development of temperature sensing materials. The phosphor excited at 318 nm shows a blue broad band emission and several red sharp peaks. The value of Bi3+→Eu3+ energy transfer can reach 98.2% when Eu3+ doping content is 0.14. Benefiting from diverse thermal response behaviors due to Bi3+ and Eu3+ ions completely different electronic configurations, a dual-emitting optical thermometer is designed. The maximum values of absolute and relative sensitivities are as high as 2.51% K−1 at 473 K and 1.43% K−1 at 423 K, respectively. The thermochromic phosphor possesses a great chromaticity shift (ΔE = 317×10−3) with temperature. Based on superior color discriminability, visual colorimetry temperature measurement relied on thermal characteristic is proposed. All the results demonstrate that YNbO 4 :0.01Bi3+, 0.005Eu3+ phosphor as a sensitive and reliable optical thermometer has great potentials in temperature measurement. [ABSTRACT FROM AUTHOR]

Single phase multiferroics are rare in nature, because ferroelectric and ferromagnetic orderings require empty d -orbits and filled d -orbits, respectively. Here we demonstrate that ferroelectricity can be induced by ion-pair doping in ferromagnetic oxide such as ferrites with filled d -orbits. Our study shows that a new kind of room temperature multiferroic can be achieved in single phase thin films of CoFe 2 O 4 with Li + -Al 3+ pair substitution of Co 2+ along 〈110〉 direction. A ferroelectric domain mechanism related to ion-pairs in co-doped thin films was revealed. Importantly, a new way for fabricating single phase multiferroic materials is provided in the present study. [ABSTRACT FROM AUTHOR]

[Display omitted] • B-TiO 2 /LDH heterojunction was successfully fabricated via in-situ hydrothermal synthesis. • B-TiO 2 /LDH delivered a superior 100% H 2 S removal efficiency by visible-light-driven photocatalysis. • B-TiO 2 /LDH exhibited high photocatalytic performance of H 2 S under different desulfurization conditions. • B-TiO 2 /LDH was demonstrated remarkable stability in a long-term desulfurization test. • The sulfate formed on B-TiO 2 /LDH was proven to boost H 2 S catalytic oxidation process. Hydrogen sulfide (H 2 S), a highly toxic, malodorous, and corrosive gas, poses a serious threat to the atmospheric environment and human health. It is highly attractive to design high-performance desulfurization photocatalyst in environmental remediation. Herein, a novel and highly efficient photocatalyst boron-doped TiO 2 combined with MgAl-Layered double hydroxides (B-TiO 2 /LDH) was synthesized via an in-situ hydrothermal method. The B-TiO 2 /LDH photocatalyst exhibited outstanding photocatalytic performance with 100% H 2 S removal efficiency within 120 min under visible light irradiation. The B-TiO 2 /LDH photocatalyst also exhibits a good H 2 S removal efficiency in different desulfurization conditions and delivers remarkable stability in a long-term test. The sulfate formed on the surface of B-TiO 2 /LDH has been shown to favor the light-enhanced catalytic oxidation process. This work provides a promising idea for effectively treating malodorous gas and shows potential of using the novel B-TiO 2 /LDH photocatalyst for future environmental remediation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Oxidation behaviour of Cr/Si co-doped NiAlDy alloys is investigated at 1200°C. [•] The effect mechanism of Si and Cr on oxidation of NiAlDy alloys is discussed. [•] NiAlDyCr–3Si reveals low oxidation rate and enhanced oxide scale adhesion. [•] Pair affinity of Si and Cr alleviates deleterious effect of Cr precipitation. [ABSTRACT FROM AUTHOR]

Abstract: Cyclic oxidation of β-NiAl alloys doped with different reactive elements (REs) each of which had an optimized concentration was investigated. All of REs effectively suppressed growth of voids beneath oxide scales formed on the alloys. The La-doped alloy suffered from severe internal oxidation. The Hf or Zr-doped alloys exhibited lower oxidation rate, while the Dy-doped alloy showed less scale rumpling. The effect mechanisms associated with solid solubility and ion size of RE dopants on cyclic oxidation were discussed. Co-doping of REs, such as Dy and Hf or Zr, could be anticipated to provide better cyclic oxidation performance. [Copyright &y& Elsevier]