Correction: A silver–manganese dual co-catalyst for selective reduction of carbon dioxide into carbon monoxide over a potassium hexatitanate photocatalyst with water

Correction for ‘A silver–manganese dual co-catalyst for selective reduction of carbon dioxide into carbon monoxide over a potassium hexatitanate photocatalyst with water’ by Xing Zhu et al., Chem. Commun., 2019, 55, 13514–13517.

Crystalline Structure, Synthesis, Properties and Applications of Potassium Hexatitanate: A Review

Potassium hexatitanate (PHT) with chemical formula K2Ti6O13 has a tunnel structure formed by TiO2 octahedra sharing edges or corners and with the potassium atoms located in the tunnels. This material has attracted great interest in the areas of photocatalysis, reinforcement of materials, biomaterials, etc. This work summarizes a large number of studies about methods to prepare PHT since particle size can be modified from millimeter to nanometric scale according to the applied method. Likewise, the synthesis method has influenced the material properties as band-gap and the final mechanical performance of composites when the reinforcement is PHT. The knowing of synthesis, properties and applications of PHT is worthwhile for the design of new materials and for the development of new applications taking advantage of their inherent properties.

Microstructure and tribological properties of epoxy composites modified by methyl silicone oil-loaded microcapsules and/or reinforced with potassium hexatitanate whiskers

Self-lubricating functional microcapsules using melamine-formaldehyde resin encapsulating methyl silicone oil as core materials were synthesized by in situ polymerization method. And they are further adopted as antifriction additive to improve the tribological properties of binary and ternary epoxy (EP) composites, which were fabricated by incorporating microcapsules and the potassium hexatitanate whiskers (PTWs) into the EP matrix. The tribological behaviors of the as-synthesized EP composites have been evaluated by means of a block-on-ring high-speed wear tester. The results demonstrated that the friction coefficient and wear rate of EP /microcapsules binary composites decreased with the increase of microcapsule concentration due to the self-lubricating effect of the core material. For the EP /microcapsules/PTWs ternary composites, not only the mechanical properties and thermal stability PTWs were improved, but also the friction reduction and antiwear effect of the ternary composite are further enhanced due to the synergistic effect of PTWs and microcapsules.

A silver–manganese dual co-catalyst for selective reduction of carbon dioxide into carbon monoxide over a potassium hexatitanate photocatalyst with water

A Ag–Mn dual co-catalyst can improve the photocatalytic activity of a K2Ti6O13 photocatalyst to a great extent for CO2 reduction to CO by using H2O as an electron donor with an extremely high CO selectivity (SCO = 98%).

Improving anti-infrared radiation and heat insulation by potassium hexatitanate whisker-doped Al 2 O 3 –SiO 2 composite xerogel

Taking potassium hexatitanate whisker (PTW) modified by silane coupling agent KH550, aluminium nitrate inorganic salt and tetraethyl orthosilicate and deionized water, respectively, as infrared sunscreen, aluminium source and raw materials forming the network structure of a composite xerogel, a series of structurally intact PTW-doped Al 2 O 3 –SiO 2 composite xerogel thermal-insulating materials were prepared by the sol–gel method and dried under atmospheric pressure. The infrared spectral characteristics, infrared radiation transmittance, microstructures, morphology and thermal conductivity of different composite materials prepared have been determined by a Fourier transform infrared spectrometer, UV–visible–near-infrared spectrophotometer, X-ray diffractometer, scanning electron microscope and thermal conductivity tester. The results exhibit that when the Al to Si molar ratio is 1 : 9, the composite material with 5 wt% modified PTW shows the best infrared radiation blocking performance and the lowest thermal conductivity (0.0604 W m −1 K −1 ).

Study on the Growth Mechanism of K2Ti4O9 Crystal

Potassium hexatitanate (K2Ti4O9) whiskers were prepared by the kneading–drying–calcination method. After the preparation of products under different calcination temperatures and holding times, their morphology and structure were characterized by thermogravimetric and differential thermal, X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy. The XRD analysis showed that the reaction mixture was completely converted to K2Ti4O9 crystals at 800 °C when the T/K ratio was 3. Based on the analysis of LS (liquid–solid) growth mechanism, the corresponding transformation reaction mechanism during the roasting was elucidated. K2Ti4O9 whiskers grow mainly through the parallel action at a low temperature. With the increase in temperature, the series effect is obvious.