Excellent Moisture Resistance Research Articles

Development of Novel Frontsheets With Protective Coatings to Increase the Durability and Reliability of Glass‐Free Lightweight PV Modules

ABSTRACTIn this work, novel PET‐based frontsheet materials with UV‐cured coatings were developed and investigated. UV‐curing urethane acrylates were selected as innovative, fluorine‐free coating systems. Polyurethane coatings exhibit excellent UV resistance, chemical and moisture resistance and, thus, high durability in outdoor applications. A homogeneous application without coating defects such as bubbles, voids or detachments was achieved. Material tests with cross‐cut tests showed no separation from the PET substrate. The water vapor transmission rates and the physical (optical and thermal) and chemical properties of the novel polymeric frontsheets were measured and compared with uncoated reference systems and products already on the market. The aging‐related changes after irradiation and humid heat storage were investigated and described in detail. Based on this comprehensive study, the newly developed frontsheets can be considered a suitable alternative to polymeric frontsheets with fluorine‐containing top layers.

Ultrasensitive Room Temperature Formaldehyde Sensors Based on F Doped ZnO Nanostructures Activated by UV Light.

It is urgent to develop an ultrasensitive formaldehyde (HCHO) sensor that can operate at room temperature and has a low detection limit. Metal oxide semiconductors are excellent gas sensitive materials. Therefore, in this paper, we present the synthesis of fluorine (F) doped zinc oxide (ZnO) porous nanomaterials through a straightforward one-pot method with the optimization of F doping levels to achieve the detection of low concentrations of HCHO under UV light at room temperature. Under 375 nm UV light, the sensor exhibits a response value of 386% to 10 ppm of HCHO, which is 2.6 times higher than that of pure ZnO, and its detection limit is as low as 75 ppb. It has excellent selectivity, stability, and moisture resistance, which can meet the requirements of HCHO detection in daily life. Analysis reveals that doping ZnO with F not only increases the material's specific surface area but also introduces active sites. Furthermore, it alters the state of HCHO on the material's surface from physical adsorption to chemical adsorption. The above reasons together enhance the adsorption of HCHO on the gas sensitive material, thereby improving its gas sensitivity performance. Overall, this work demonstrates that F-doped ZnO is a potential material for ultrasensitive HCHO sensors and provides insights into the interpretation of the effect of doping on the gas sensitivity properties of materials.

Linearly programmable two-dimensional halide perovskite memristor arrays for neuromorphic computing.

The exotic properties of three-dimensional halide perovskites, such as mixed ionic-electronic conductivity and feasible ion migration, have enabled them to challenge traditional memristive materials. However, the poor moisture stability and difficulty in controlling ion transport due to their polycrystalline nature have hindered their use as a neuromorphic hardware. Recently, two-dimensional (2D) halide perovskites have emerged as promising artificial synapses owing to their phase versatility, microstructural anisotropy in electrical and optoelectronic properties, and excellent moisture resistance. However, their asymmetrical and nonlinear conductance changes still limit the efficiency of training and accuracy of inference. Here we achieve highly linear and symmetrical conductance changes in Dion-Jacobson 2D perovskites. We further build a 7 × 7 crossbar array based on analogue perovskite synapses, achieving a high device yield, low variation with synaptic weight storing capability, multi-level analogue states with long retention, and moisture stability over 7 months. We explore the potential of such devices in large-scale image inference via simulations and show an accuracy within 0.08% of the theoretical limit. The excellent device performance is attributed to the elimination of gaps between inorganic layers, allowing the halide vacancies to migrate homogeneously regardless of grain boundaries. This was confirmed by first-principles calculations and experimental analysis.

Effect of Diatomite on the Mechanical and Electrical Properties of Polyurethane/Epoxy Resin Composites

ABSTRACT Epoxy resin is widely utilized for the encapsulation of power semiconductor devices, necessitating excellent insulation properties, mechanical performance, and moisture resistance. In this study, hexadecyltrimethoxysilane was employed to modify diatomite, which was then combined with polyurethane-modified epoxy resin to fabricate a series of filled composites with varying diatomite content. The influence of diatomite content on the mechanical properties, thermal properties, and insulation performance of the polyurethane/epoxy resin composites was investigated. Experimental results showed that, under the synergistic effect of polyurethane and diatomite, the composite containing 4 wt.% diatomite exhibited improvements of 13.95% and 61.11% in tensile strength and flexural strength, respectively, compared to the epoxy resin. The elongation at break and flexural displacement also increased by 22.46% and 68.23%, respectively. Furthermore, the incorporation of diatomite effectively compensated for the thermal losses caused by polyurethane, enhancing thermal stability. Electrical property tests indicated that the addition of diatomite reduced the dielectric constant and conductivity of the epoxy resin while simultaneously improving its breakdown strength.

Au-sensitized metal–organic framework-derived indium-doped zinc oxide for highly enhanced trimethylamine sensing

Preparation of a gas sensor capable of rapidly and accurately detecting trimethylamine is crucial for environmental monitoring, food safety and human health. In this study, Au-In-ZnO with an irregular nanoparticle structure was prepared using simple metal–organic-framework synthesis method and in-situ reduction process. The Au-In-ZnO sensor exhibited a high response of 260.2 to 100 ppm trimethylamine at 250 °C, which is 32 times higher than that of pristine ZnO (350 °C), with the optimal operating temperature lowered by 100 °C. Meanwhile, the sensor had a short response time (2 s), enabling it to quickly react to leaked trimethylamine during practical applications. Additionally, the sensor also possessed low detection limit (0.3 ppm, Rair/Rgas=2.0), high selectivity, excellent moisture resistance, good repeatability, and long-term stability. The mechanism of gas-sensitive properties enhancement was analyzed in combination with the conduction mechanism of hypervalent ions and the electronic and chemical sensitization of noble metals. This study provides a potential gas-sensitive material for the efficient measurement and rapid evaluation of trimethylamine.

A novel Cr3+-doped MgGaBO4 phosphor: Expanding the horizons in plant illumination

Near-infrared (NIR) spectroscopy technology has demonstrated unparalleled efficacy in night vision, iris authentication, plant illumination, food inspection, and various other domains. Nonetheless, the quest for novel phosphors exhibiting superior luminescent efficiency and enduring thermal stability persists as a formidable obstacle. In this study, phosphors MgGaBO4: Cr3+, Al3+ were successfully synthesized by high-temperature solid-phase reaction method. Firstly, starting from MgGaBO4: Cr3+, the crystal field environment around Cr3+ ions was modulated by replacing Ga3+ with Al3+ to further improve the luminescence performance of the phosphor. The emission peak wavelength of MgGaBO4: 0.0075Cr3+,0.005Al3+ phosphor was about 756 nm, the full width at half-maximum (FWHM) was about 174 nm under the blue light excitation of 440 nm. In addition, the luminescence intensity at 100 °C remains at 77.41 % of that at room temperature. Finally, the excellent moisture resistance of this phosphor was demonstrated. This work not only introduces a novel broadband NIR phosphor with promising application potential in advanced agricultural lighting but also proposes a synergistic enhancement strategy for effectively improving the performance of broadband NIR phosphor-converted LED light sources.

Fabrication of MoS2-Fe3O4 heterostructure as an ultrafast and high-sensitivity NO2 gas sensor at room temperature

In this study, a novel MoS2-Fe3O4 heterostructure was fabricated for efficient detection of NO2 gas. The structural and morphological properties of MoS2-Fe3O4 composites were investigated by relevant characterization methods. The NO2 sensing performance of the sensor based on MoS2-Fe3O4 was tested. The result demonstrated that the MoS2-Fe3O4 sensor showed excellent performance with a high response of 25 and a fast response time of 6 s as exposed to 5 ppm NO2 at room temperature. In addition, this sensor also exhibited high sensitivity, satisfactory selectivity, excellent moisture resistance, favorable reproducibility and long-term stability. The enhanced gas sensing performance can be attributed to the synergetic effect of the abundant oxygen vacancy and p-n heterojunction.

Flexible, Breathable and Hydrophobic SnO2–SnS2–SiO2/SiO2 All‐Inorganic Self‐Supporting Nanofiber Membrane for Ultralow‐Concentration NO2 Sensing Under High Humidity

AbstractInorganic semiconductor gas sensors, being widely utilized in gas‐sensing applications, face significant challenges in attaining mechanical flexibility and humidity resistance in wearable sensing fields. Herein, a highly flexible, breathable, and hydrophobic all‐inorganic self‐supporting nanofiber (NF) gas sensor is developed using electrospinning combined with thermal sulfidation approach. This innovative sensor features a bilayer configuration, with an amorphous SiO2 nanofiber substrate layer and an interwoven SiO2 and SnO2–SnS2 nanofiber active layer. The relatively low elastic modulus of the amorphous SiO2 nanofibers, combined with the three‐dimensional network interwoven structure, endow the SnO2–SnS2–SiO2/SiO2 sensor with superior mechanical flexibility. The sensor exhibits excellent sensitivity, selectivity, moisture resistance, and cycling stability (>10 000 cycles at 140° bending) to both high and low concentration NO2. Notably, an excellent flexible detecting capability of the sensor to NO2, an asthma‐related biomarker, is demonstrated at ultralow concentrations (≈25 ppb) in simulated exhaled breath environments. The enhanced moisture resistance is attributed to the effective inhibition of hydrogen bond formation from H2O molecules by the Sn─S bonds formed through sulfidation of SnO2 nanofibers. This work represents a substantial advancement in the universal fabrication of flexible, breathable and moisture‐resistant inorganic semiconductor sensors for wearable breath sensing applications.

An advanced ceramifiable organic-inorganic hybrid polysiloxane coating with superior moisture-resistant property

A ceramifiable organic-inorganic hybrid polysiloxane, prepared via a straightforward solution blending method, was successfully coated on the surface of silicon dioxide ceramic via a scrapping method. A uniform and dense lithium aluminum borosilicon (LABS) vitrified layer in situ formed on the surface of silicon dioxide ceramics was successfully prepared through liquid phase filling method to fulfill the moisture resistance requirements under high temperature cycle conditions. Effects of aluminum content on the microstructure change process and moisture resistance properties of the ceramifiable organic-inorganic hybrid polysiloxane have been systematically researched. With the increase of aluminum content, the ceramic yield of the hybrid polysiloxane and the heat loss capacity of LABS glass-ceramics increase. The crack-free and high temperature fluid vitrified layer endows the LABS glass-ceramic with excellent thermal shock resistance cycle ability, self-healing ability and moisture resistance. Results showed that the LABS vitrified coating with an aluminum-boron ratio of 1:2 presents the most appealing thermal shock cycle resistance and crack self-healing ability after 20 thermal cycles, as well as a water absorption rate of 0.3814 %. By refining the application of modified polysiloxane moisture-resistant coatings in high-temperature circulation environments, this work shed lights on the importance of in situ growth LABS vitrified coating in accelerating surface reconstruction and improving moisture resistance, incenting additional innovative breakthroughs in the LAS-based glass-ceramic materials design and fabrication within the aviation field.

Preparation of an environment-friendly microbial limestone dust suppressant and its dust suppression mechanism.

The development of an efficient and environmentally friendly dust suppressant is crucial to address the issue of dust pollution in limestone mines. Leveraging the synergistic microbial-induced calcium carbonate precipitation (MICP) technology involving NaHCO3 and dodecyl glucoside (APG), the optimal ratio of the dust suppressant was determined through single-factor and response surface tests. The dust suppression efficacy and mechanisms were analyzed through performance testing and microscopic imaging techniques, indicating that the optimal ratio of the new microbial dust suppressant was 20% mineralized bacteria cultured for 72h, 0.647molL-1 cementing solution, 3.142% NaHCO3, and 0.149% APG. Under these conditions, the yield of calcium carbonate increased by 24.89% as compared to when no NaHCO3 was added. The dust suppressant demonstrated excellent wind, moisture, and rain resistance, as well as curing ability. More calcite was formed in the dust samples after treatment, and the stable form of the dust suppressant contributed to consolidating the limestone dust into a cohesive mass. These findings indicate that the synergistic effect of NaHCO3 and APG significantly enhanced the dust suppression capabilities of the designed microbial dust suppressant.

Hydrothermal synthesis of NdFeO3 nanoparticles and their high gas-sensitive properties

N-butanol, a volatile organic compound prevalent in numerous industrial processes, poses significant risks to human health and the environment if not properly monitored. Consequently, the development of high-sensitivity n-butanol sensors is imperative. For this reason, NdFeO3 nanoparticles were successfully synthesized by hydrothermal method and used for the detection of n-butanol. They were fully analyzed using characterization techniques such as XRD, BET, EDX, SEM, TEM and XPS. The test results revealed that the prepared samples exhibited a granular structure with an average diameter of approximately 65 nm. The specific surface area measured 15.415 m2/g, and the pore size was determined to be 16.638 nm. The NdFeO3 sensor responds up to 441 for 100 ppm n-butanol at 260 °C, response and recovery times were 33 s and 7 s respectively. The response value of the NdFeO3 sensor is still 4.3 for 1 ppm n-butanol with a minimum detection limit of 0.024 ppm. Simultaneously, the NdFeO3 sensor has excellent selectivity, stability and moisture resistance. These good sensing properties indicate that this work provides a possible strategy for developing an economical and repeatable high performance gas sensor for the detection of n-butanol.

Aluminum Carboxylate Modification Enabled Efficient and Stable Perovskite-Polystyrene Thin Films for Light-Emitting Applications.

Lead halide perovskite nanocrystals (PNCs) have demonstrated great potential in emerging display technologies. However, the practical application of PNCs is hindered by the inherent instability of their ionic surface. Here, we proposed a surface modification approach to enhance the stability of CsPbBr3 PNCs by postsynthetic treatment with aluminum phenylbutyrate (Al(PA)3). Our study reveals that Al(PA)3 displaces ammonium ligands and binds tightly on surface halide, providing excellent air and moisture resistance while preserving a high quantum efficiency of 81.6%. The modified PNCs maintain a constant photoluminescence intensity under continuous UV light illumination for 500 h. Additionally, the Al(PA)3 ligand is compatible with styrene, enabling homogeneous dispersion of PNCs in polystyrene matrices to form bright and uniform PNC-PS thin films. We demonstrated the application of the composite films for display backlighting, which exhibits a wide color gamut of 125% NTSC. The result highlights the potential of AlPA-modified PNCs in light-emitting and other optoelectronic devices.

Heterostructure engineering of In2O3/ErVO4 hairy curd for high-performance TEA gas sensors

Triethylamine (TEA) is a mephitic volatile organic compound, which has huge damage to human body. Therefore, the development of gas sensitive materials for the effective detection of TEA has important application value. In this paper, In2O3, ErVO4 and In2O3/ErVO4 composite samples were successfully synthesized by hydrothermal method. The In2O3/ErVO4 composite of In2O3 and ErVO4 has a spherical structure with a rough surface, and forms a variety of porous structures, which effectively increases the specific surface area of the composite (58.9551m2/g), thereby improving the gas sensitivity to TEA. In2O3/ErVO4 composites can achieve a higher response to 100 ppm TEA (S = 54.73), have a lower optimal operating temperature (250 °C) compared with In2O3 pure samples, and have a faster recovery time (52 s) compared with ErVO4 pure samples. In addition, In2O3/ErVO4 sensors also achieve good selectivity, excellent moisture resistance, long-term stability. The microstructure of the sample was significantly changed by ErVO4 recombination. These alterations include an increase in specific surface area, a decrease in particle size, an increase in the utilization of the sensitive body, an increase in the proportion of vacancy oxygen, a decrease in the optical band gap, and an increase in electron transport efficiency. These results show that the combination of ErVO4 and In2O3 to construct heterojunction can achieve excellent sensor for TEA gas detection.

SnO2 nanoparticles-decorated In2O3 and their enhanced acetone gas sensing properties

There are many articles on gas sensor research (Zhang et al., 2023; Sheng et al., 2022; Ma et al., 2023; Yuan et al., 2024) [1–4]，Me asuring the acetone content of exhaled breath can reflect changes in blood sugar in the body. Therefore, it is of great value to develop gas sensitive materials for detecting acetone gas effectively. In this paper, by adding SnO2 to In2O3. composite In2O3/SnO2 microspheres were prepared. Using XRD, SEM, TEM, XPS, PL and UV technology, the microstructure morphology and optical properties of In2O3/SnO2 were measured. The experimental results showed that the composite retained the advantages of In2O3 and SnO2 optimized the properties of the composite effectively, and reduced the photoluminescence intensity. The gas sensitive properties of In2O3/SnO2 composite samples were tested. The test results showed that compared with pure In2O3 samples, the optimal working temperature of In2O3/SnO2 was reduced by 30 °C–250 °C. The response value to acetone gas is increased to about 35. In addition, In2O3/SnO2 sensors also achieve good selectivity excellent moisture resistance. long-term stability. These results show that the heterojunction of SnO2 and In2O3 can be used as an excellent sensor for detecting acetone gas.

Study on the tribological properties of hexagonal boron nitride flakes composite hydrophilic/hydrophobic ionic liquids films by self-assembly

Due to the weak out-of-plane van der Waals interaction between layers, hexagonal boron nitride (h-BN) with a stacking structure has been proven to be a promising lubrication material for its friction performance. However, obtaining h-BN composite films with excellent substrate bonding and low friction properties under high humidity remains challenging. Ionic liquids (ILs) composed of anions and cations that are liquid at or near room temperature have distinguished themselves in the field of lubrication (lubricating additives and lubricating films) due to their advantages of low saturated vapor pressure, good stability and high viscosity. Based on the relationship between lubrication performance and hygroscopicity of hydrophilic/hydrophobic ILs, a simple and flexible method for preparing h-BN composite hydrophilic/hydrophobic ILs films on metal substrates has been developed. h-BN has excellent antioxidant and moisture resistance as well as lubrication performance. Consequently, the influence of the hygroscopicity of ILs on the macroscopic tribological performance of h-BN composite hydrophilic/hydrophobic ILs films was investigated. The results showed that PVA/BNOH composite hydrophobic ILs films displayed a lower friction coefficient and outstanding wear resistance than those of PVA/BNOH composite hydrophilic ILs films in both atmosphere and high humidity. The synergies between the film layers, the intrinsic differences between the hydrophilic and hydrophobic ILs, and tribo-chemical reactions at friction interfaces greatly promoted the realization of excellent tribological performance of composite films. Additionally, the tribological properties of these films at high humidity were mainly related to the interaction between water molecules and the ILs.

Doping with KBr to Achieve High-Performance CsPbBr3 Semitransparent Perovskite Solar Cells.

Wide-bandgap semitransparent perovskite photovoltaics are emerging as one of the ideal candidates for building-integrated photovoltaics (BIPV). However, surface defects in inorganic CsPbBr3 perovskite prepared by vapor deposition severely limit the optoelectronic performance of perovskite solar cells. To address this issue, a strategy of doping a trace amount of KBr into perovskite by vapor deposition is adopted, effectively improving the quality of the film, reducing surface defect concentration, and enhancing the transportation and extraction of charge carriers. Simultaneously, fully physical vapor deposition technology is employed to fabricate perovskite solar cells with an average visible light transmittance of 44%. These devices exhibited an ultrahigh open-circuit voltage of 1.55 V and a superior power conversion efficiency (PCE) of 7.28%, demonstrating excellent moisture and heat resistance. Moreover, the corresponding 5 cm × 5 cm modules achieve a PCE of 5.35% with great thermal insulation capability. This work provides an approach for fabricating highly efficient all-inorganic perovskite solar cells with high average visible light transmittance, demonstrating new insights into their application in building-integrated photovoltaics.

Effect of Operational Variables on Supercritical Foaming of Caffeic Acid-Loaded Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) Blends for the Development of Sustainable Materials.

Expanded polystyrene will account for 5.3% of total global plastic production in 2021 and is widely used for food packaging due to its excellent moisture resistance and thermal insulation. However, some of these packages are often used only once before being discarded, generating large amounts of environmentally harmful plastic waste. A very attractive alternative to the conventional methods used for polymer processing is the use of supercritical carbon dioxide (scCO2) since it has mass-transfer properties adapted to the foam morphology, generating different path lengths for the diffusion of active compounds within its structure and can dissolve a wide range of organic molecules under supercritical conditions. The objective of this research was to evaluate the effect of operational variables on the process of caffeic acid (CA) impregnation and subsequent foaming of polylactic acid (PLA) as well as two PLA/poly(butylene-co-terephthalate-adipate) (PBAT) blends using scCO2. The results showed an increase in the degree of crystallinity of the CA-impregnated samples due to the nucleation effect of the active compound. On the other hand, SEM micrographs of both films and foams showed significant differences due to the presence of PBAT and its low miscibility with PLA. Finally, the results obtained in this work contribute to the knowledge of the important parameters to consider for the implementation of the impregnation and foaming process of PLA and PLA/PBAT blends with potential use in food packaging.

Improvement of mechanical and thermal expansion properties of pectinase treatment plant fiber reinforced starch/PBAT composites

AbstractThis study discussed the impact of pectinase treatment on the properties of starch/PBAT composite, using two types of plant fibers such as coconut coir and bamboo fibers. The fibers underwent pretreatment with pectinase assisted by ultrasonics, and the composite was subsequently produced through hot pressing. The research focused on evaluating the thermal properties, mechanical properties, moisture absorption properties, and microstructure of the resulting composites. The findings revealed that the inclusion of pectinase‐treated plant fibers significantly enhanced the composite's strength. In particular, the bending strength of the composite with 15 wt% bamboo fibers exhibited the highest improvement, registering a 65% increase compared to the composite without added fibers. Additionally, the linear expansion coefficient of the plant fiber composite treated with pectinase was notably lower than that without added fibers. Among these, the linear expansion coefficient of the 15 wt% coir fiber composite decreased by 73.4% in the temperature range of 40–80°C compared to the composite without added fibers. The observed effects were attributed to the pectinase treatment, which proved effective in disrupting the network structure of cell walls, eliminating pectin components from fibers, and facilitating enhanced interaction between the fillers and the polymer matrix.Highlights The inclusion of fibers significantly enhanced the composite's strength. 10 wt% of bamboo fibers had a greater impact on the composite's strength than coir fiber. The linear expansion coefficient of the plant fiber composite decreased. The composite with 5 wt% bamboo fiber demonstrated excellent moisture resistance. The pectinase treatment enhanced interaction between fillers and matrix.

Multi-scale modified PVDF/Ag@C layer based on dielectric doping and plasma treatment for high-performance triboelectric nanogenerators and self-powered water sterilization

The limitations of dielectric properties and surface electron affinity and the harsh environment including high humidity, high salt content, and biological fouling restricted the efficient ocean energy harvesting of triboelectric nanogenerators (TENGs). Here, Ag@C dielectric doping and two-step O2+CF4 plasma treatment are applied to achieve multi-scale modification of triboelectric materials. The coating of C shell avoided the agglomeration of Ag NPs. Besides, the amorphous C shell inhibited the formation of electron transport pathways, and the mechanism of suppressing dielectric loss of triboelectric layers were clarified via DFT calculations at the particle (Ag@C)-polymer (polyvinylidene difluoride, PVDF) interface. The surface charge density of plasma treated polyvinyl alcohol (PVA)-PVDF/Ag@C-based TENG (PT-TENG) increased from 64.26 µC/m2 to 216.60 µC/m2, representing a significant breakthrough in energy harvesting efficiency. The mechanism of enhanced triboelectric properties was investigated based on modified Overlapped Electron Cloud model. Besides, DFT was applied to analyze the reaction mechanism in depth and predict the products of chemically-surface modification process. The oxygen-containing functional groups introduced by O2 plasma treatment likely serve as a "bridge" for the second-step grafting, which helps to build a more convincing reaction mechanism. The superhydrophobic PVDF/Ag@C exhibited excellent moisture-resistance, salt-resistance, and anti-bioadhensive properties, with outstanding charge density (321.45 µC/m2) at 95% RH, making it very suitable for energy harvesting in harsh marine environments. Moreover, the water sterilization system based on PT-TENG demonstrated a high sterilization rate of 98.74%, which was significantly higher than conventional AC power (89.96%).

Mn4+-activated (K1-xCsx)2NbF7 red phosphors with high color purity and excellent moisture resistance for WLEDs

Recently, Mn4+-activated fluoride red phosphors have received intensive attention due to their excellent luminescence properties. However, poor moisture resistance hinders their commercial application. Herein, (K1-xCsx)2NbF7:Mn4+ phosphors were designed and synthesized. All the obtained samples are rod-like microcrystals with monoclinic phase structure, Cs+-doping concentration has little influence on the microstructure while significantly impacts their luminescence properties. Specially, the composition optimized (K1-xCsx)2NbF7:Mn4+ (x = 0.3) phosphor has the color purity of 94.20 %, the quantum yield of 53.90 % and the decay lifetime of 3.59 ms. More importantly, the optimized phosphor can maintain 83.20 % of the initial emission intensity after being immersed in distilled water for 1440 min, showing the excellent moisture resistance. A warm WLED with high CRI of 85 and low CCT of 4362 K is achieved by coating the obtained optimized red phosphor in chip. Our work demonstrates that the (K1-xCsx)2NbF7:Mn4+red phosphors possess a great potential application in warm WLEDs.