The broadband optical absorption of LaFeO 3 can be effectively enhanced through bandgap and structural engineering. In this study, LaFeO 3 , La[Formula: see text]Ca[Formula: see text]FeO 3 , and La[Formula: see text]Ca[Formula: see text]FeO 3 @NiCo 2 O 4 microspheres were successfully synthesized via hydrothermal methods. Among them, the La[Formula: see text]Ca[Formula: see text]FeO 3 @NiCo 2 O 4 microspheres exhibit a flower-like morphology, with NiCo 2 O 4 nanosheets uniformly distributed on their surfaces. Ca[Formula: see text] doping significantly enhances the optical absorption of LaFeO 3 , while the incorporation of NiCo 2 O 4 further strengthens the absorption intensity. As a result, La[Formula: see text]Ca[Formula: see text]FeO 3 @NiCo 2 O 4 achieves an average absorptivity of approximately 95% in the wavelength range of 200–2500[Formula: see text]nm. Overall, the synergistic effects of bandgap modulation and surface structure engineering enhance the broadband optical absorption of LaFeO 3 -based materials, demonstrating their potential for high-performance photothermal conversion.
The electrochemical CO 2 reduction reaction (eCO 2 RR) provides a promising route for converting CO 2 into value-added chemicals and fuels. In this work, we systematically investigate a series of La[Formula: see text]M[Formula: see text]CuO 4 (M [Formula: see text] Ca, Sr, Ba) catalysts to elucidate the role of alkaline-earth metal doping in enhancing eCO 2 RR performance. Their phase structures, catalytic activities, and reaction intermediates are characterized. Electrochemical evaluations reveal that among the doped catalysts, Ca-doped La 2 CuO 4 (Ca-LC) delivers the highest selectivity toward C[Formula: see text] products, achieving a Faradaic efficiency of 61.2% at −1.4[Formula: see text]V (versus RHE) and exhibiting a C[Formula: see text]/C 1 ratio 2.1 times higher than that of undoped La 2 CuO 4 . Electrochemical analysis further indicates that Ca-LC and Sr-LC possess a larger electrochemically active surface area. In-situ infrared (IR) spectroscopy reveals that, compared with undoped La 2 CuO 4 , Ca-LC shows a more pronounced *OCCO peak, indicating more efficient *CO dimerization and thereby promoting C-C coupling and the formation of C[Formula: see text] products.
Solid chloride electrolytes with simultaneously high structural stability and rapid chloride-ion conduction are highly desirable for next-generation energy storage systems, yet their development remains a critical challenge. Herein, we report a Sb-doped CsSnCl 3 solid electrolyte through a Sn-site substitution strategy to overcome the intrinsic instability of Sn-based chloride perovskites while maintaining efficient Cl − transport. Sb incorporation suppresses structural distortion and stabilizes the cubic phase, while the accompanying chloride-rich composition provides abundant mobile Cl − carriers. The optimized CsSn[Formula: see text]Sb[Formula: see text]Cl[Formula: see text] electrolyte exhibits excellent low-temperature phase stability, a wide electrochemical stability window of 5.91[Formula: see text]V, a low activation energy of 0.23[Formula: see text]eV, and a high room-temperature ionic conductivity of 2.39[Formula: see text] × [Formula: see text]10[Formula: see text] [Formula: see text]S[Formula: see text]cm[Formula: see text], outperforming previously reported Bi-doped (1.3[Formula: see text] × [Formula: see text]10[Formula: see text] [Formula: see text]S[Formula: see text]cm[Formula: see text] and Na-doped (2.1[Formula: see text] × [Formula: see text]10[Formula: see text] [Formula: see text]S[Formula: see text]cm[Formula: see text] counterparts. This work demonstrates an effective strategy to overcome the trade-off between structural stability and ionic conductivity through dopant engineering and defect regulation, providing new insights into the design of high-performance halide solid electrolytes.
The presence of sodium (Na) and potassium (K) in sintering flue gas can severely inhibit the activity of Fe–Mn/AC catalysts during the selective catalytic reduction (SCR) of NO via CO [Formula: see text] NH 3 coupling. This study investigated the individual and synergistic poisoning effects of Na and K on the physicochemical properties and performance of Fe–Mn/AC catalysts. The results revealed that under conditions of 150–300 ∘ C and 9% O 2 , Na- and K-poisoned Fe–Mn/AC catalysts exhibited decreased NO conversion and a corresponding decline in N 2 selectivity. The degree of deactivation followed the order 0.05Na [Formula: see text] 0.05K–3.5Fe-7.0Mn/AC > 0.1K–3.5Fe–7.0Mn/AC > 0.1Na–3.5Fe–7.0Mn/AC. Comprehensive characterization (SEM-EDS, Brunauer–Emmett–Teller (BET), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy) revealed that Na and K poisoning caused surface roughening, pore blockage, and agglomeration of active components, resulting in a significant reduction in specific surface area (from 583 to 510[Formula: see text]m 2 /g) and total pore volume. Meanwhile, the contents of Fe[Formula: see text] and Mn[Formula: see text] decreased significantly, accompanied by a decrease in surface oxygen species, ultimately disrupting the redox cycles of active components. In addition, the synergistic poisoning by Na and K degraded oxygen-containing functional groups –OH and C[Formula: see text]O, substantially reducing their abundance and inhibiting the synergistic reaction between Fe and Mn on the catalyst surface. This poisoning also reduced the mobility of O[Formula: see text] species, resulting in a loss of active sites, which inhibited the SCR reaction. The coexistence of Na and K produced a synergistic poisoning effect that was stronger than individual poisoning effects, owing to enhanced occupation of active sites and disruption of electron transfer at the Fe–O–Mn interface. This study provides novel mechanistic insights into alkali-induced catalyst deactivation and offers guidance for the development of alkali-resistant SCR catalysts for industrial flue gas treatment.
The development of efficient oxygen reduction reaction (ORR) catalysts, aimed at displacing precious metal-reliant materials, constitutes a critical and persistent challenge within sustainable energy conversion technologies. In this study, a bimetallic single-atom (SA) catalyst (SAC) composed of adjacent Fe and Ni SA active sites anchored on two-dimensional (2D) nitrogen-doped carbon nanosheets (FeNi/NC) was constructed via a combination of templating and pyrolysis methods. The catalyst demonstrates outstanding ORR performance, achieving a half-wave potential of 0.92 V, which exceeds those of monometallic SA Fe-N X or Ni-N X counterparts, and commercial Pt/C. Experimental results indicate that the adjacent Fe and Ni SA sites possible function synergistically, leading to an optimized adsorption/desorption of reaction intermediates. The unique 2D nanosheet architecture with open double-sided surfaces provides abundant exposed active surfaces, facilitates efficient mass and charge transport, and improves active site accessibility. This study establishes a viable strategy for fabricating high-performance ORR electrocatalysts, while offering critical perspectives on the rational design of dual-metal single atom catalysts for sustainable energy applications.
