High Near-Infrared Reflectance Orange Pigments of Fe-Doped La₂W₂O₉: Preparation, Characterization, and Energy Consumption Simulation

Abstract

A new series of orange highly near-infrared reflective pigments based on Fe-doped La 2 W 2 O 9 were effectively fabricated via solution combustion synthesis. The acquired pigment powders were characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Xray photoelectron spectroscopy, ultraviolet−visible−near-infrared spectrophotometry, and CIE 1976 L*a*b* color scales. Then, the energy consumption of the air-conditioning system was simulated based on EnergyPlus software. The results showed that the doping of Fe 3+ ions will change the color of the pigment from white to orange. Meanwhile, the band gaps of La 2 W 1.85 Fe 0.15 O 9-δ and La 2 W 1.8 Fe 0.2 O 9-δ shifted from 3.71 to 3.07 eV and 2.96 eV, respectively. The typical La 2 W 1.85 Fe 0.15 O 9-δ pigment powders showed the highest near-infrared reflectance of 89.25% between 700 and 2500 nm and impressive color (L* = 74.20, a* = 22.69, and c* = 22.42). The simulation results illustrated that the homeowner could save $7.32 per month by coating the walls and roofs of the building with the energy-saving paint composed of La 2 W 1.8 Fe 0.2 O 9-δ . Excellent chemical stability and high near-infrared reflectance made the synthesized pigments a potential candidate for energy-saving coatings.

The Spin Modulation Stimulated Efficient Electrocatalytic Oxygen Evolution Reaction over LaCoO3 Perovskite

“…Significantly, a gradual increase of Co 2+ /Co 3+ can be observed when the post thermal reduction time is prolonged, which may be attributed to the spin state transition and charge compensation. The O 1s spectra illustrated in Figure 3d and Figure S10 can be deconvoluted into three peaks, which are assigned to the lattice oxygen atoms (O L ), defective oxygen (O v ) and surface adsorbed oxygen (O c ), respectively [43] . Obviously, with the post thermal reduction time, the concentration of defective oxygen also increases.…”

Cool Surface Strategies with an Emphasis on the Materials Dimension: A Review

“…On the other hand, the development of new compositions of reflective pigments continues to increase, reaching more potential evaluations. In addition to the high reflectivity, the research field has also been evaluating the functional and long-term performances against surface contamination [69], thermal insulation [70,71], and the synthesis methods in terms of the energy and raw material costs, which were directed for the sol-gel method and rare-earth compounds [72][73][74][75][76][77].…”

Ion Substitution Strategy toward Spectral Tunability of Environmentally Friendly Rare Earth Sulfide Lattices for Radiative Cooling

“…Therefore, it is important to develop materials capable of meeting people's aesthetic needs and achieving energy efficiency in buildings. 9,10 Pigments are an indispensable presence in life as part of the rich lives of people, and inorganic pigments containing heavy metal ions such as chromium and lead have excellent properties, but their toxicity to the human body cannot be ignored. Due to its features of pigments with no toxicity, strong coloring power, good dispersion, etc.…”

“…Nowadays, dense building complexes and sparse surface vegetation in cities can increase radiant heat exchange in hot environments, eventually creating an urban heat island effect and forcing people to overuse air conditioning to cope with the hot summer. – In energy distribution of solar radiation, vis near-infrared (NIR) light accounts for 94% of total solar radiation, indicating that applying materials with higher NIR reflectivity to building envelopes is a promising strategy to alleviate the urban heat island effect. – However, despite the excellent cooling effect of Al or Ag materials with high heat reflection or commercial coatings TiO 2 , they cannot meet people’s aesthetic needs, thus hindering their practical application. Therefore, it is important to develop materials capable of meeting people’s aesthetic needs and achieving energy efficiency in buildings. , …”