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Lactic acid is an important organic acid with wide applications, and preparation of lactic acid from biomass-derived 1,2-propanediol was considered a green reaction route. In this paper, a Cu modified Au/γ-Al2O3 catalyst was designed for the oxidative esterification of 1,2-propanediol to methyl lactate in an alkali-free methanol system. The structural properties of the Au–Cu/γ-Al2O3 catalyst were characterized by various characterization methods, and interaction between Au nanoparticles and Cu species was discovered. Moreover, the catalytic tests showed that the Cu modified Au/γ-Al2O3 catalysts exhibited higher methyl lactate selectivity than the monometallic Au/γ-Al2O3 catalyst. It was revealed that the synergistic effect between the Au nanoparticles and Cu species could promote the oxidation of primary hydroxyl groups of 1,2-propanediol to produce methyl lactate and reduce the generation of by-products. In addition, a reasonable reaction pathway for the oxidative esterification of 1,2-propanediol was proposed based on the comparative experiments. These findings may provide favorable guidance for design of Au based nanocatalysts for the oxidative esterification of alcohols to esters and carboxylic acids. [ABSTRACT FROM AUTHOR]

Luminescent thermometers provide a non-contact method of probing temperature with high sensitivity and response speed at the nanoscale. Synergistic photoluminescence from different activators can realize high sensitivity for luminescent thermometers by finely selecting ions with specific crystallographic sites. Herein, the more temperature-sensitive Mn4+ and the less-sensitive Eu3+ (or Sm3+) activators are co-doped into a Ca2GdSbO6 matrix to form an effective thermometer, where Mn4+ and Eu3+ (or Sm3+) ions occupy the Sb5+ and Gd3+ sites, respectively. The co-doping of Eu3+ ions or Sm3+ ions leads to lattice expansion of Ca2GdSbO6 matrix and a tuned narrow emission from deep-red to orangish-red. According to the ratio of luminescence intensity, the maximal Sa and Sr values are 0.19 K−0 (347 K) and 1.38% K−( (420 K) for Ca2GdSbO6:Mn4+/Eu3+ probe and 0.26 K−p (363 K) and 1.55% K−( (430 K) for Ca2GdSbO6:Mn4+/Sm3+ probe thermometers, respectively. In addition, thermometers based on Mn4+ emission lifetimes can provide the highest relative sensitivity of 1.47% K−s at 425 K. Thus, the highly-temperature-sensitive Ca2GdSbO6:Mn4+/(Eu3+ or Sm3+) phosphor is a promising candidate for practical luminescence thermometers. [ABSTRACT FROM AUTHOR]

Luminescent thermometers provide a non-contact method of probing temperature with high sensitivity and response speed at the nanoscale. Synergistic photoluminescence from different activators can realize high sensitivity for luminescent thermometers by finely selecting ions with specific crystallographic sites. Herein, the more temperature-sensitive Mn 4+ and the less-sensitive Eu 3+ (or Sm 3+ ) activators are co-doped into a Ca 2 GdSbO 6 matrix to form an effective thermometer, where Mn 4+ and Eu 3+ (or Sm 3+ ) ions occupy the Sb 5+ and Gd 3+ sites, respectively. The co-doping of Eu 3+ ions or Sm 3+ ions leads to lattice expansion of Ca 2 GdSbO 6 matrix and a tuned narrow emission from deep-red to orangish-red. According to the ratio of luminescence intensity, the maximal S a and S r values are 0.19 K -0 (347 K) and 1.38% K -( (420 K) for Ca 2 GdSbO 6 :Mn 4+ /Eu 3+ probe and 0.26 K -p (363 K) and 1.55% K -( (430 K) for Ca 2 GdSbO 6 :Mn 4+ /Sm 3+ probe thermometers, respectively. In addition, thermometers based on Mn 4+ emission lifetimes can provide the highest relative sensitivity of 1.47% K -s at 425 K. Thus, the highly-temperature-sensitive Ca 2 GdSbO 6 :Mn 4+ /(Eu 3+ or Sm 3+ ) phosphor is a promising candidate for practical luminescence thermometers.

A three-dimensional cross-linked Ni-V 2 O 5 nanomaterial with a particle size of 250-300 nm was successfully prepared in a 1-butyl-3-methylimidazole bromide ionic liquid (IL). The formation of this structure may follow the rule of dissolution-recrystallization and the ionic liquid, as both a dissolution and structure-directing agent, plays an important role in the formation of the material. After calcination of the precursor, the active material (Ni-V 2 O 5 -IL) was used as an anode for lithium-ion batteries. The designed anode exhibited excellent electrochemical performance with 765 mA h g -1 at a current density of 0.3 A g -1 after 300 cycles, which is much higher than that of a NiVO-W material prepared via a hydrothermal method (305 mA h g -1 ). These results show the remarkable superiority of this novel electrode material synthesized in an ionic liquid., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)