RESUMEN
In order to deal with the global energy crisis and environmental problems, reducing carbon dioxide through artificial photosynthesis has become a hot topic. Lead halide perovskite is attracted people's attention because of its excellent photoelectric properties, but the toxicity and long-term instability prompt people to search for new photocatalysts. Herein, a series of <111> inorganic double perovskites Cs4 Mn1-x Cux Sb2 Cl12 microcrystals (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) are synthesized and characterized. Among them, Cs4 Mn0.7 Cu0.3 Sb2 Cl12 microcrystals have the best photocatalytic performance, and the yields of CO and CH4 are 503.86 and 68.35 µmol g-1 , respectively, after 3 h irradiation, which are the highest among pure phase perovskites reported so far. In addition, in situ Fourier transform infrared (FT-IR) spectroscopy and electron spin resonance (ESR) spectroscopy are used to explore the mechanism of the photocatalytic reaction. The results highlight the potential of this class of materials for photocatalytic reduction reactions.
RESUMEN
The application of X-ray imaging in military, industrial flaw detection, and medical examination is inseparable from the wide application of scintillator materials. In order to substitute for lead, lower costs, and reduce self-absorption, organic-inorganic hybrid lead-free perovskite scintillators are emerging as a new option. In this work, novel (TEA)2Zr1-xTexCl6 perovskite microcrystals (MCs) were successfully synthesized by a hydrothermal method, with Te4+ doping, which leads to yellow triplet-state self-trapped excitons emission. The emission peak of (TEA)2Zr1-xTexCl6 located at 605 nm under X-ray excitation, which was applied to X-ray imaging, shows a clear wiring structure inside the USB connector. The detection limit (DL) of 820 nGyair/s for (TEA)2Zr0.9Te0.1Cl6 is well below the dose rate corresponding to a standard medical X-ray diagnosis is 5.5 µGyair/s. This work opens up a new path for organic-inorganic hybrid lead-free scintillators.
RESUMEN
Although dielectric barrier discharge (DBD) plasma is a promising technique for CO2 conversion, realizing CO2-to-alcohol is still challenging via the use of H2O. Herein, for the first time, efficient CO2 conversion was achieved via the synergism between the Cs2SnCl6 photocatalyst and DBD plasma assisted by H2O. The CO2 conversion ratio of plasma photocatalysis was 6.5% higher than that of only the plasma and photocatalysis, implying that the synergism of plasma catalysis and photocatalysis was achieved. Furthermore, the DBD plasma assisted by the Cs2SnCl6 photocatalyst could convert CO2 and H2O to CO and a small amount of methanol and ethanol. The CO2 conversion ratio was enhanced by 50.6% in the presence of H2O, which was attributed to the improvement of charge transfer due to the increased electrical conductivity of the photocatalyst surface during plasma discharge. This work provides a new idea for developing an efficient system for CO2 utilization.
RESUMEN
Lead halide perovskites are prospective candidates for CO2 photoconversion. Herein, we report copper-doped lead-free Cs2AgSbCl6 double perovskite microcrystals (MCs) for gas-solid phase photocatalytic CO2 reduction. The 0.2Cu@Cs2AgSbCl6 double perovskite MCs display unprecedented CO2 photoreduction capability with CO and CH4 yields of 412 and 128 µmol g-1, respectively. The ultrafast transient absorption spectroscopy reveals the enhanced separation of photoexcited carriers in copper-doped Cs2AgSbCl6 MCs. The active sites and reaction intermediates on the surface of the doped Cs2AgSbCl6 are dynamically monitored and precisely unraveled based on the in-situ Fourier transform infrared spectroscopy investigation. In combination with density functional theory calculations, it is revealed that the copper-doped Cs2AgSbCl6 MCs facilitate sturdy CO2 adsorption and activation and strikingly enhance the photocatalytic performance. This work offers an in-depth interpretation of the photocatalytic mechanism of Cs2AgSbCl6 doped with copper, which may provide guidance for future design of high-performance photocatalysts for solar fuel production.
RESUMEN
It is still challenging to design and develop the state-of-the-art photocatalysts toward CO2 photoreduction. Enormous researchers have focused on the halide perovskites in the photocatalytic field for CO2 photoreduction, due to their excellent optical and physical properties. The toxicity of lead-based halide perovskites prevents their large-scale applications in photocatalytic fields. In consequence, lead-free halide perovskites (LFHPs) without the toxicity become the promising alternatives in the photocatalytic application for CO2 photoreduction. In recent years, the rapid advances of LFHPs have offer new chances for the photocatalytic CO2 reduction of LFHPs. In this review, we summarize not only the structures and properties of A2 BX6 , A2 B(I)B(III)X6 , and A3 B2 X9 -type LFHPs but also their recent progresses on the photocatalytic CO2 reduction. Furthermore, we also point out the opportunities and perspectives to research LFHPs photocatalysts for CO2 photoreduction in the future.
RESUMEN
Lead halide perovskite materials have great potential for photocatalytic reaction due to their low fabrication cost, unique optical absorption coefficient, and suitable band structures. However, the main problems are the toxicity and instability of the lead halide perovskite materials. Therefore, a facile synthetic method is used to prepare lead-free environmentally friendly Cs2 TiX6 (X = Cl, Cl0.5 Br0.5 , Br) perovskite materials. Their structural and optical characteristics are systematically investigated. The band gaps of the produced samples are illustrated to be from 1.87 to 2.73 eV. Moreover, these materials can keep high stability in harsh environments such as illumination and heating, and the Cs2 Ti(Cl0.5 Br0.5 )6 microcrystals demonstrate the yields of 176 µmol g-1 for CO and 78.9 µmol g-1 for CH4 after light irradiation for 3 h, which is of the first report of Ti-based perovskite photocatalysts. This finding demonstrates that the Ti-based perovskites will create opportunities for photocatalytic applications, which may offer a new idea to construct low-cost, eco-friendly, and bio-friendly photocatalysts.
RESUMEN
In response to calling for a sustainable and carbon-neutral economy, the conversion of CO2 to useful chemicals using the solar energy is a potential tactic to relieve the global energy dilemma and environmental issues, which has been a hot topic so far. Recently, the lead halide perovskites as novel photocatalysts have attracted researchers' interests. However, they generally encounter poor stability and lead toxicity, restricting their large-scale practical applications. Here, the lead-free Cs2TeX6 (X = Cl, Cl0.5Br0.5, Br, Br0.5I0.5, and I) perovskite microcrystals with strong stability were prepared and used to realize the CO2 photocatalytic reduction efficiently. The prepared Cs2TeBr6 microcrystals delivered stronger photocatalytic ability than many previously reported photocatalysts, with the CO and CH4 yields of 308.63 and 60.42 µmolg-1, respectively, under 3 h of illumination. The presented strategy in our work provides new ideas of designing and preparing efficient and practical CO2 reduction photocatalysts based on nonleaded and high-stability halide perovskites.
RESUMEN
Organic-inorganic hybrid perovskites have attracted extensive attention for potential memory applications because of their excellent properties, such as high charge carrier mobility and fast ion migration. Herein, the two-dimensional HAPbI4 perovskite with an octahedral structure and high stability was prepared by a facile solution method. Moreover, the resistive random access memory (RRAM) with the Ag/PMMA/HAPbI4/ITO structure has been successfully fabricated by spin coating and vacuum thermal evaporation. The as-prepared RRAM device based on HAPbI4 demonstrated superior resistive switching performance. The on/off ratio is as high as 105, and the corresponding retention of the device exceeds 10â¯000 s; furthermore, the RRAM device could be kept stable after being kept in the air for 24 weeks.
RESUMEN
Carbon dioxide utilization activated by the integration of plasma and photocatalyst is a promising approach to achieve the mitigation of the greenhouse effect. In this paper, for the first time, the dielectric barrier discharge (DBD) plasma and halide perovskite photocatalysts were synergistically used to facilitate the carbon dioxide conversion. After introducing the photocatalyst into the plasma reactor, the plasma discharge characteristics were improved by the photocatalyst while the active photons, electrons, and vibrationally excited molecules in plasma also enhanced the photocatalytic activity of the photocatalyst. Compared with pure CsPbBr3 and Al2O3, the CsPbBr3@TiO2 with the best photocatalytic activity also exhibited the best performance in plasma. The carbon dioxide conversion rate of the DBD plasma filled with CsPbBr3@TiO2 was found to be 29.6% higher than the sum of sole plasma and photocatalysis, illustrating the achievement of the synergistic effect between the plasma and photocatalyst. This work brings up new opportunities for efficient large-scale conversion and utilization of carbon dioxide by the coupling of nonthermal plasma and photocatalysis.
RESUMEN
Exploring photocatalysts to foster CO2 photoreduction into high value-added chemicals is of great significance. Lead halide perovskites (LHPs) have recently been extensively investigated as photocatalysts, owing to their facile fabrication and prominent optoelectronic properties. However, the toxicity of lead and instability will hinder their future large-scale applications. To address these challenges, a series of lead-free Sb-based all-inorganic mixed halide perovskite Cs3 Sb2 (Brx I1- x )9 (0 ≤ x ≤ 1) nanoplatelets (NPLs) is synthesized. The perovskite NPLs are prepared using a ligand-assisted re-precipitation approach at 50 °C. The authors observe the tunability of their optical band gaps from 2.1 to 2.5 eV, and they can maintain the excellent stability over 120 h under heating at 100 °C or UV light irradiation. The resultant materials are employed as efficient photocatalysts for visible-light driven CO2 reduction at the gas-solid interface. The Cs3 Sb2 (Br0.7 I0.3 )9 perovskite NPLs afford an impressive overall yield of 27.7 µmol g-1 for the selective photocatalytic conversion of CO2 into CO. This study represents a significant demonstration for practical artificial photosynthesis by using LHP materials as photocatalysts.
RESUMEN
Nowadays, there is much attention focusing on lead halide perovskite because of its admirable performances in optoelectronic applications. However, the notorious toxicity and long-term instability are two main factors limiting its widespread applications. The findings of this work demonstrate a facile synthesis process for novel lead-free CsAgCl2 perovskite microcrystals with no organic ligand involved. The fundamental properties of the CsAgCl2 microcrystals are revealed by applying temperature-dependent X-ray diffraction and photoluminescence measurements from 77 to 300 K. Furthermore, the CsAgCl2 microcrystals exhibit excellent air (60 days), thermal (100 °C), and light stability. Meanwhile, the CsAgCl2 microcrystals have shown exciting potential applications in the fields of photocatalysis and photoelectrochemistry.
RESUMEN
Halide perovskites are potential humidity-detection materials due to their sensitivity to water, but the instability of traditional lead-based halide perovskites and the toxicity of Pb hinder further application in humidity sensing. Here, lead-free Cs3Cu2Br5 perovskite microcrystals passivated by surface ligands (OLA and OAm) are used to prepare an environmentally friendly humidity sensor. The humidity sensing performance of the prepared sensors was tested, and the effect of surface ligands of perovskites on the performance of humidity sensors was analyzed. The results show that the impedance variations of the manufactured humidity sensors at 12 to 95% relative humidity are 106Ω (OLA) and 105Ω (OAm), respectively. Besides, the sensors demonstrated excellent repeatability, low hysteresis, and considerable stability at different RH values. Furthermore, the analysis of the different ligands attests that short-chain OLA is more conducive to the formation of porous films with stronger water absorption capacity, further improving the responsiveness of the sensor. By contrast, and long-chain OAm is more conducive to the formation of dense films, improving the response ability at low humidity. Additionally, the more hydrophilic OLA contributes to greater responsiveness, while the more hydrophobic OAm helps to shorten the response and recovery time.
