Search

High near-infrared (NIR) reflective pigments have broad application prospects in alleviating urban heat island effect. But in fact, an easy and efficient method of preparing non-toxic and high near-infrared reflective pigments remains a desired choice for energy-saving coatings. In this research, several Mn doped YBO 3 pigments, possessing gray-blue and high near-infrared reflectance, were effectively prepared by solution combustion method. Relevant techniques were used to characterize the crystalline structure, morphology feature, optical properties, chemical tolerance, and heat insulation effect of the prepared pigments. The results presented that the color of powders varied from white to gray-blue due to the Mn doping. The band gap energy increased from 2.03 eV to 2.14 eV as the doping amount raised, and it could be assigned to the charge transfer transition between O 2p valence bands and Mn 3d conduction bands. The typical YB 0.97 Mn 0.03 O 3 pigment stated the excellent near-infrared reflectance of 66.18% and significant color properties (L* = 69.75, a* = −5.46, and b* = −6.36). Notably, the surface temperature of YB 0.97 Mn 0.03 O 3 coating is 39.5 °C lower than the gray-blue commercial pigmented coating. This work demonstrated that the prepared pigments with rather high reflectance possessed potential application in energy-saving materials for buildings. [ABSTRACT FROM AUTHOR]

Superfine CaLaAl 1-x Cr x O 4 (x = 0.02, 0.05, 0.08, 0.10) red ceramic pigments have been prepared by solution combustion reaction and subsequent high-temperature calcination. All of the pigments were characterized by X-ray diffraction (XRD), Field scanning electron microscopy (FESEM), UV–Vis spectrophotometry, Laser particle size analyzer and CIE L*a*b* spectrophotometry. Moreover, the effects of the doping amount of Cr3+ ion, calcination temperature, salt assistance and synthetic routes on chromatic performance and particle size distributions of the pigments were also investigated. The results showed that CaLaAl 1-x Cr x O 4 pigment particles prepared via solution combustion reaction and subsequent calcination were well-dispersed and uniform in size. With the increase of doping amount of Cr3+ ion, the brightness value L* of CaLaAl 1-x Cr x O 4 pigments decreased obviously and the redness value a* increased gradually. When x = 0.08, it showed the best chromatic performance (L* = 39.37, a* = 21.33, b* = 13.99). In addition, the synthetic pigments possess excellent high temperature stability which is conducive to the application of ceramic pigments. Most importantly, the synthetic method of CaLaAl 1-x Cr x O 4 red ceramic pigments is not only cheap in raw materials, but also easy to industrialize. [ABSTRACT FROM AUTHOR]

Abstract To further enhance electrochemical performance of WS 2 -based materials in supercapacitors, a 3D architecture with WS 2 nanoflakes interconnected and quantum dots anchored on N and S co-doped reduced graphene oxide (WS 2 /N,S-rGO) crumpled nanosheets is fabricated for the first time via a novel, facile and scalable approach, which is based on rapid solution combustion synthesis of the precursor and subsequent gas-solid phase sulfurization, and needs no such tedious processes as filtration, washing and drying. Significantly, the WS 2 /N,S-rGO hybrid possesses a specific capacitance of 1562.5 F g−1 at 1 A g−1 and a rate capability of 780 F g−1at 40 A g−1, which are superior to the currently-reported WS 2 -based electrode materials. As to the WS 2 /N,S-rGO hybrid, the 3D hierarchical architecture, synergistic effect between WS 2 and N,S-rGO nanosheets as well as nitrogen and sulfur co-doping on rGO offer a variety of advantages such as larger contact surface area, shorter ion diffusion path, excellent charge transport and especially the enhanced pseudo-capacitance of rGO, and thus result in huge improvement in electrochemical activity, which demonstrate the WS 2 /N,S-rGO hybrid to be a superb anode material in supercapacitors. Graphical abstract 3D WS 2 /N,S-rGO hybrid with superior performance in supercapacitor was fabricated for the first time via a facile and scalable approach based on solution combustion and subsequent sulfurization. Unlabelled Image Highlights • 3D hybrids of WS 2 /N,S co-doped reduced graphene oxide (rGO) are fabricated for the first time. • The synthetic route is based on two steps of solution combustion and sulfurization. • WS 2 nanoflakes and QDs are interlinked with N,S-rGO sheets to form a 3D structure. • The hybrids exhibit a high specific capacitance of 1562.5 F g−1 at 1 A g−1 in SCs. • An excellent rate capability of 780 F g−1at 40 A g−1 is achieved when used in SCs. [ABSTRACT FROM AUTHOR]