Incorporation Of Cr Research Articles

Corrosion Ferritic Stainless Steel in a Simulated Hydrothermal Liquefaction Bioconversion Aqueous Solution: Effect of Surface Cr Content

Abstract The objective of this study was to determine the effect of surface Cr content on the corrosion of ferritic stainless steels in hot pressurized alkaline water (310 °C at 10 MPa) simulating a hydrothermal liquefaction bioconversion medium. Two methods to increase the Cr surface content were investigated: (i) selecting commercial grades of ferritic stainless steel with an increasing Cr content and (ii) applying a Cr coating (chromizing) to a low-Cr (Type 409) ferritic stainless steel. The observed parabolic-like corrosion kinetics were analyzed and discussed in terms of the structure and composition of the double layered oxide films that formed. The (surface) Cr content is a critical factor affecting corrosion. Corrosion was reduced by 66% (after 20 days exposure) when increasing the Cr content from 9 wt.% (P91) to 21 wt.% (SS443) in the commercial grades of ferritic stainless steel. Moreover, corrosion was reduced by 84% (after 20 days exposure) by chromizing the surface of a low-Cr (Type 409) ferritic stainless steel. Improved corrosion protection was attributed to increased Cr incorporation into the inner (barrier) Fe(Fe1-nCrn)2O4 layer, with the formation of a Cr2O3 layer (resulting from chromizing) being most beneficial.

Studies of Structural, Impedance, Modulus Spectroscopy, and Magnetic Properties of Cr‐Modified SrTiO3 Perovskite Ceramic

This study investigates the effects of chromium inclusion on the structural, microstructural, frequency dependent electrical and magnetic properties of SrTiO3 perovskite. The composition of Sr1−xCrxTiO3 (SCT) ceramics with x = 0.00, 0.02, 0.04 is preapred via a high‐temperature solid‐state reaction route. Rietveld refinement of X‐ray diffraction data revealed a cubic structure with space group . All SCT samples have been analyzed for Cr incorporation at the Sr‐site using Raman and Fourier transform infrared spectroscopy. Field‐emission scanning electron microscopy studies probed a gradual increase in grain size due to the uniform distribution of dopants across sample surfaces, as confirmed by energy‐dispersive X‐ray spectroscopy analysis. Cr doping strongly influences the electrical properties of grain and grain boundary resistance. All samples undergo Arrhenius‐type transport via oxygen ion migration and mixed conduction (ionic/electron), whereas relaxation occurs through mixed‐type association () and (). The magnetic nature of Cr‐doped samples confirms room‐temperature ferromagnetism due to carrier‐associated oxygen vacancies and Ruderman‐Kittel‐Kasuya‐Yosida interaction. These findings investigate Cr doping as mixed‐ionic and electronic conductors for intermediate temperature‐solid oxide fuel cells and spintronics‐based semiconductor devices.

Rational design of chromium-doped NiFe phosphide/phosphate heterostructures for inhibiting chloride ion adsorption and achieving alkaline seawater splitting at industrial-level current density

Electrocatalysts with high activity and corrosion resistance, tailored for industrial-grade current densities, played a crucial role in seawater electrolysis. Here, we synthesized a petal-like Cr-doped NiFe phosphate 'semi-coated' phosphide heterostructure electrocatalyst grown on nickel foam (Cr-NiFeP/PO3@NF). This catalyst demonstrated superior catalytic performance in natural seawater, maintaining stability and only a slight increase in cell voltage after operating continuously for 100 h at a current density of 1 A cm−2. The incorporation of Cr introduced a significant number of unpaired electrons, which enhanced the conductivity of the catalyst, facilitated the creation of electron depletion regions around Ni and Fe, and improved the interaction with adsorption intermediates. Furthermore, the high activity and corrosion resistance during the oxygen evolution reaction (OER) were due to the interaction between the in-situ formed high-valent phosphate and NiFeCrOOH during the anodization process.

Highly catalytic performance for the selective C–H bond oxidation of p-chlorotoluene over Co, Cr co-doped OMS-2 catalyst

Using O2 as an oxidant, developing a non-noble metal catalyst for the selective catalytic C–H bond oxidation of p-chlorotoluene is desirable and challenging. In this work, a series of Co, Cr co-doped OMS-2 (Octahedral Molecular Sieve-2) catalysts were prepared by a conventional refluxing method. It was found that the incorporation of Co and Cr improved the catalytic activity for the selective oxidation of p-chlorotoluene to p-chlorobenzaldehyde. Among these catalysts, CoCr/OMS-2 (Co: Cr = 1: 1, mass ratio), the best catalyst, shows that the conversion and the selectivity of p-chlorobenzaldehyde is 94.8 % and 94.3 %, respectively. The enhanced catalytic activity was due to the larger specific surface area and even dispersion of active components. The characterization results also disclosed that the co-doping of Co and Cr increased the oxygen vacancy and enhanced the ability to activate the surface lattice oxygen. Additionally, density functional theory calculations demonstrated that co-doping of Co and Cr promoted the adsorption of p-chlorotoluene and O2, and decreased the energy barrier of rate-determining step (the conversion of p-chlorobenzyl alcohol to p-chlorobenzaldehyde). Besides, when H2O was added to the reaction system as the second solvent, the activation and dissociation of O2, and the formation of p-chlorobenzaldehyde were facilitated, in agreement with the experimental results. This work demonstrated the promotional effect of Co, Cr co-doped into OMS-2 catalyst and the role of H2O for the selective oxidation of p-chlorotoluene.

Enhanced high-temperature corrosion resistance of Cr-modified phosphate/aluminum powder composite coatings: Mechanisms and thermodynamic insights

Phosphate composite coatings are regarded as one of the tangible solutions for surface protection in salt spray environments, benefiting from their cost-effectiveness and prominent structure stability upon high-temperature exposure. However, rapid curing of these coatings often leads to crack formation, and the underlying corrosion mechanisms in service conditions remain insufficiently understood, limiting their practical applications. In this study, we developed chromium-incorporated phosphate/aluminum powder composite (Cr-P/Al) coatings and evaluated their corrosion resistance under alternating conditions of salt spray corrosion and oxidation at 450 °C. By integrating experimental results, ab initio calculations, and thermodynamic analysis, we demonstrate that the incorporation of Cr significantly enhances the performance of the P/Al coatings. The structural evolution was first revealed that Cr’s modification reduced tensile stress and prevented cracks in the coating. A mixed layer of amorphous oxides and phosphates forms on the surface of the Al powder, providing robust binding strength. A novel corrosion mechanism was identified that Cl2 and volatile chlorides facilitated the removal of Cl-. This process is more ineffective with Cr-P/Al coating, as amorphous Cr oxide has low reactivity at a high log[p(Cl2)] and low log[p(O2)] compared with amorphous Mg and Fe oxide, thereby enhancing the corrosion resistance of the coating. These coating densification methods and corrosion protection mechanisms provide a critical foundation for the future application of phosphate composite coatings.

Investigating thermal and UV ageing effects on crumb rubber modified bitumen enhanced with emission reduction agents and carbon black

Over time, bitumen experiences deterioration due to factors like the exposure to oxygen, solar irradiation, and temperature fluctuations. While laboratory techniques like rolling thin film oven (RTFO) and pressure ageing vessel (PAV) were developed to simulate field ageing, they do not accurately replicate environmental factors normally occurring in the field, particularly solar irradiation. Limited research has focused on understanding the ageing processes of crumb rubber modified bitumen (CRMB). This study investigated how different ageing conditions affect the chemo-rheological properties of CRMB and CRMB with geopolymer-based fly ash (GFA), Portland cement paste (PCP), and carbon black (CB). GFA and PCP were added to reduce noxious fumes and VOC emissions from CRMB whereas CB is commonly employed as an antioxidant agent. RTFO and PAV were used to simulate short- and long-term ageing, while a SUNTEST XLS+ weatherometer was used for thermal and UV ageing simulations. A dynamic shear rheometer and attenuated total reflectance Fourier transform infrared spectroscopy were employed for rheological and chemical analysis. Results indicated that extended exposure to thermal conditioning and UV irradiation had the most impact on the chemo-rheological properties of the binders. The incorporation of CR into bitumen enhanced ageing resistance and mitigated the potential for stiffening and embrittlement. The addition of GFA, PCP, and CB to CRMB had a negligible impact on the chemo-rheological properties when subjected to RTFO, PAV, and thermal conditioning. However, following UV ageing, these additives led to a slight increase in carbonyl bonds and greater stiffness compared to pure CRMB

Transition metal-doped modification of lattice defects in formaldehyde catalysts − Controlling the specific surface area and mass transfer

Exploring room temperature treatment of formaldehyde (HCHO) is a crucial area of ongoing research, with transition metal catalysts showing promise for future development due to their cost-effectiveness. However, the challenge lies in the limited ability of these catalysts to activate oxygen efficiently and maintain stable catalytic oxidation of HCHO. The Mn3O4 catalyst doped with Cr, Cu, Zn, and Co was synthesized via hydrogen reduction in this study. Cr/Mn3O4 showed exceptional catalytic performance by completely converting HCHO at 30 °C and 200 ppm, while maintaining excellent stability during a 75-hour durability test. The characterization techniques revealed that the incorporation of transition metal Cr into the Mn3O4 lattice resulted in an increased number of oxygen vacancy defects on its surface, thereby significantly enhancing its ability to activate oxygen. Furthermore, Cr doping substantially augmented the specific surface area and abundance of mesoporous structures in the catalyst, which provided ample active sites and facilitated efficient mass transfer for substrate oxidation by promoting diffusion to these active sites. These enhancements ultimately led to a heightened activation of oxygen and H2O into reactive oxygen species, consequently reducing the dominance of side reaction pathways caused by intermediates occupying active sites.

Chrome incorporation in high-pressure Fe–Mg oxides

Abstract. The occurrence of Cr-bearing oxide phases as inclusions in diamonds and in extraterrestrial materials has the potential to serve as an indicator of formation conditions. However, such an application requires detailed knowledge of phase stabilities and the influence that Cr may have on its stability. To this end, the incorporation of Cr in high-pressure post-spinel Fe–Mg oxide phases was experimentally investigated at pressures of 14–22 GPa and temperatures between 1100 and 1600 °C using a multi-anvil press. We find that neither the Fe3Cr2O6 nor the Mg3Cr2O6 endmember composition is stable over the expected range of pressure and temperature where Fe5O6 itself is known to be stable. Further experiments along the Fe32+Fe23+O6–Fe32+Cr2O6 binary indicate only small amounts of Cr substitution are possible: ∼ 0.12 cations Cr per formula unit or ∼ 6 mol % Fe32+Cr2O6 component. In contrast, complete solid solution is apparent across both the Fe22+(Cr,Fe3+)2O5 and the Mg2(Cr,Fe3+)2O5 binaries, and there are indications of complete solution in the entire (Mg,Fe2+)2(Cr,Fe3+)2O5 quaternary system. The O5-structured phase usually coexists with (Fe,Mg)O. At 16–20 GPa, a post-spinel phase with O4 stoichiometry was occasionally encountered, having either a modified Ca-ferrite- (mCF-FeCr2O4) or a Ca-titanate-type (CT-MgCr2O4) structure. In one high-temperature experiment at 1600 °C, an unquenchable Mg-rich phase with a reconstructed Mg4Fe23+O7 stoichiometry occurred together with Mg2(Cr,Fe3+)2O5. In one experiment at 1100 °C and 16 GPa with a bulk composition of Mg2(Cr0.6,Fe0.43+)2O5, an assemblage of O5 phase + eskolaite–hematite solid solution + periclase was obtained together with minor amounts of the CT-type phase and a β-(Cr,Fe)OOH phase. The occurrence of these two minor phases in this low-temperature experiment is an indicator of variable reaction kinetics amongst the starting materials, which caused chemical heterogeneities to develop at the onset of the experiment. The structural systematics of Fe22+(Cr,Fe3+)2O5 and (Fe2+,Mg)2(Cr,Fe3+)2O5 solid solutions were investigated. It is notable that the Fe3+ and Cr endmembers have somewhat different crystal structures, belonging to space groups Cmcm (no. 63) and Pbam (no. 55), respectively. The phase transition occurs around the midpoint of the Fe3+–Cr joins. In spite of complexities in the behavior of the unit-cell parameters, the variation in molar volume with composition deviates only slightly from linearity. Wüstite and periclase coexisting in our experiments reveal the incorporation of up to 9 wt % and 25 wt % Cr2O3, respectively. This is consistent with the minor Cr contents reported for some ferropericlase inclusions in natural diamond. The limited solubility of other cations in Fe5O6 limits the likelihood of it being an accessory phase in the Earth's deep upper mantle and transition zone, except in Fe-rich environments. In contrast, the O5 phase appears to be more flexible in accommodating a range of divalent and trivalent cations, suggesting that this phase is more likely to be stabilized, potentially where redox reactions related to diamond formation occur.

Chromium nano-segregation and intermediate band formation in heavily-doped ZnS:Cr films

X-ray absorption spectroscopy, X-ray diffraction, and UV–Vis spectroscopy were employed to investigate heavily-doped ZnS:Cr films prepared by RF magnetron co-sputtering. EDS indicates ca. 5 at. % Cr incorporation as well as slight S-deficiency. XAS in the Zn K- and Cr K-edges revealed Zn-by-Cr substitution and segregation of Cr nanoclusters which lead to significant lattice distortion. XRD indicates a 44 % increase in the strain, an increase in the lattice parameter, and a decrease in the crystallite size upon Cr incorporation. The presence of Cr nanoclusters contributed to changes in the band gap, a large Urbach tail parameter of 565 meV, and the formation of an intermediate band arising from the Cr 3d spin-up states. The results suggest ZnS:Cr films in the heavily doping regime could lead to applications in photovoltaics and spintronics.

Enhancing strength and ductility in Fe–20Mn–9Al-1.5C austenitic low-density steels through Ni and Cr alloying synergy adding

In this investigation, a Fe–20Mn–9Al-1.5C lightweight austenitic steel has been developed through strategic alloying with Ni and Cr elements coupled with the employment of a thermo-mechanical processing technique featuring ultra-fast cooling. This composition and treatment synergistically transcend the conventional trade-off between strength and ductility, positioning the mechanical performance of this steel notably above that of comparable low-density austenitic steels previously reported. The coordinated incorporation of Ni and Cr is key to modulating the precipitation threshold for nanoscale κ-carbides and LRO domains, achieving an optimal size for precipitate-induced strengthening. The incorporation of Cr specifically contributes to a dual enhancement mechanism: it fosters the generation of high-density dislocation arrays (HDDA) and refines the dynamic slip band (DSBR) during deformation, which in turn, elevates the strain hardenability and ductility. The remarkable synergy in strength and ductility is attributed to a combination of mechanisms including grain boundary reinforcement, solid solution hardening, the precipitation strengthening effect of nanoscale precipitates, and the activation of secondary slip system dislocations. This synergy is quantitatively reflected in the material's yield strength (YS) exceeding 1100 MPa, ultimate tensile strength (UTS) surpassing 1200 MPa, and a total elongation (TEL) exceeding 45%. The insights gained from this research provide critical guidance for the design and creation of austenitic low-density steels that do not compromise between strength and ductility, thereby offering superior overall performance.

Enhanced thermoelectric performance of Cr-doped ZnSb through lattice thermal conductivity reduction below the phonon glass limit

Zinc antimonide (ZnSb) is a promising thermoelectric material due to its economic viability, elemental abundance, and superior phase stability compared to other Zn-Sb compounds. However, its widespread application is hindered by a low figure-of-merit (zT). Extensive research has explored doping, alloying, and nanostructuring to improve zT. This study investigates the impact of Cr doping in CryZn1-ySb (y = 0.0 – 0.03). Cr doping with y = 0.01 significantly reduces lattice thermal conductivity below the phonon glass limit. Debye-Callaway model calculations suggest a combined effect of point defects and decreased grain size caused by Cr incorporation. This reduction translates to enhanced thermoelectric performance, with the y = 0.01 sample exhibiting a 70 % improvement in zT at 673 K, reaching ∼0.67. Exceeding the Cr substitution limit leads to the formation of a detrimental secondary CrSb2 phase, increasing thermal conductivity. The Single Parabolic Band model calculations predict further zT enhancement in y = 0.01 sample to ∼0.2 at 300 K through optimized carrier concentration (307 % improvement in zT). These findings demonstrate the potential for significant zT improvement in ZnSb via defect engineering and carrier concentration tuning.

Effect of biochar-derived DOM on contrasting redistribution of chromate during Schwertmannite dissolution and recrystallization

Biochar-derived dissolved organic matter (BDOM), is extensively involved in the recrystallization of minerals and the speciation alteration of associated toxic metals. This study investigates how BDOM extracted from tobacco petiole (TP) or tobacco stalk (TS) biochar influences the speciation repartitioning of Cr(VI) in environments impacted by acid mine drainage (AMD), focusing on interactions with secondary minerals during Schwertmannite (Sch) dissolution and recrystallization. TP-BDOM, rich in lignin-like substances, slowed down the Cr-Sch dissolution and Cr release under acidic conditions compared to TS-BDOM. TP-BDOM's higher O/C component exerts a delayed impact on Cr-Sch stability and Cr(VI) reduction. In-situ ATR-FTIR and 2D-COS analysis showed that carboxylic and aromatic N-OH groups in BDOM could interact with Cr-Sch surfaces, affecting sulfate and Cr(VI) release. It was also observed that slight recrystallization occurred from Cr-Sch to goethite, along with increased Cr incorporation into secondary minerals within TS-BDOM. This enhances our understanding of BDOM's role in Cr(VI) speciation changes in AMD-contaminated sites.

Crystallization behavior and structural characteristics of Cr-doped Sb70Se30 thin films for phase change memory

In this study, we prepare Cr-doped Sb70Se30 (SS) thin films via the magnetron sputtering. The influence of Cr doping on the crystallization behavior and structure characteristics of the SS thin films is systematically studied using a combination of experimental analyzes and theoretical calculations. The results reveal that compared with SS thin films, Cr-doped SS thin films exhibit higher crystallization temperature, better data retention capability, larger crystallization activation energy, and reduced resistance drift coefficient. In addition, the incorporation of Cr effectively suppresses grain growth in the SS thin films and refines the grain size. The electrical transport properties of the Cr-doped SS thin films are analyzed using a Hall system. Both X-ray photoelectron spectroscopy and first-principles calculations indicate that Cr is more prone to occupy Sb atoms and form stronger Cr–Se bonds, consequently enhancing the stability of the SS thin films. Raman spectroscopy confirms that the introduction of Cr leads to a decrease in bond length and an increase in bond energy. Moreover, the Cr-doped SS thin film exhibits minimal volume fluctuations and a smoother surface morphology, resulting in enhanced interface performance and reliability. Taken together, these results indicate that the introduction of Cr is an effective strategy for optimizing the properties and modifying the structures of SS phase-change materials.

Enhancing the oxygen evolution reaction activity of Iron (oxy)hydroxide by increasing reactive sites with morphology modulation

Nonprecious transition metal (oxy)hydroxides play a vital role in accelerating the kinetics of sluggish oxygen evolution reaction (OER). The fast electron transfer from the electrocatalyst material surface to the electrode is key to obtaining improved OER activity in terms of improved reaction kinetics and reduced overpotential. Therefore, it is highly desirable to design electrocatalysts with efficient electron transport properties. Here, an approach of modulation of the morphology of Iron (oxy)hydroxide through the incorporation of Cr is used to obtain high electrocatalytic activity. The incorporation of Cr resulted in the modified morphology of Iron (oxy)hydroxide with the formation of a porous pit-like structure which offers large reactive sites to effectively adsorb the reactants and allow an efficient electron transfer pathway from electrocatalyst to circuit through Ni foam electrode. A 50 % Cr incorporated electrocatalyst (Fe5.0Cr5.0 (oxy)hydroxide) exhibits excellent OER activity with an overpotential of 237 mV and 297 mV at current densities of 10 and 100 mA cm─2, respectively owing to fast electron transport from electrocatalyst to substrate due to formation of porous pit-like structure. Furthermore, Fe5.0Cr5.0 electrocatalyst shows high durability of over 100 h at 10 mA cm─2. The enhanced OER activity is attributed to the effect of Cr incorporation and morphology modulation which helps to modulate the electronic structure as well as electrocatalytic active sites of Fe (oxy)hydroxide. The systematic incorporation and modulation of morphology pave the way for designing future electrocatalysts for various electrochemical activities.

Reduction and transformation of Cr(VI)-associated ferrihydrite by Shewanella oneidensis MR-1: Kinetics and secondary minerals

Hexavalent chromium (Cr(VI)) could be sequestrated by soils via microbial reduction to Cr(III) and association with minerals, however, quantitative understanding of metal reducing bacteria on the coupled kinetics of Cr and Fe minerals is still lacking. Here, microbial-mediated ferrihydrite transformation and reductive sequestration of Cr(VI) were investigated with Shewanella oneidensis MR-1 under varying Cr/Fe ratios. Quantitative results depicted that the contents of magnetite from ferrihydrite transformation decreased from 70 % to 22 % after 288 h as Cr/Fe ratios increased from 0 to 8 × 10−3, and reductive transformation rates increased with decreasing Cr/Fe ratio. Elemental mapping and line scan analyses at nano-scale revealed that Cr(VI) was evenly combined within fresh ferrihydrite, and a part of produced Cr(III) was doped into the crystal lattice of magnetite and goethite. Cr may be sequestrated by secondary Fe minerals via structural substitution, surface complexation, and physical encapsulation. Microscopy-based results exhibited that more Fe minerals adsorbed on the surface of cell and less cells were lysed at low Cr/Fe ratios. Confocal laser scanning microscopy depicted that less cells were alive at high Cr/Fe ratios. The amplification of extracellular electron transfer-associated genes was downregulated as Cr/Fe ratios increased. The Cr/Fe ratios could affect cell activity, the combination with Fe minerals, and Mtr gene expression, thus controlling the reductive sequestration of Cr(VI) and phase transformation of ferrihydrite. A kinetic model has been established by combining elementary reductions, and it could well describe Cr(VI) reduction and Cr(III) incorporation under various Cr/Fe ratios during dissimilatory Fe reduction process. These findings could broaden our knowledge of quantifying the migration and transport of Cr in anoxic Cr-contaminated soil environments, and could be useful for simulating Cr dynamic behaviors in the natural soil, aquatic, and sediment environments.

Performance and properties evolution of near-term accident tolerant fuel: Cr-doped UO2

Chromium-doped UO2 fuel has received significant interest due to the ability for chromium to produce pellets with large average grain size (>30 μm), which has shown to increase fission gas retention during operation. Sintering of chromium-doped UO2 pellets was pursued with oxygen potential and sintering atmosphere controlled to tailor the final microstructure of the material. Chromium additions in this study ranged from 750 to 7800 ppm. Cr concentrations were studied pre and post sintering using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Effects of chromium content on lattice parameter and microstructure were examined with X-ray diffraction (XRD) and scanning electron microscopy (SEM). Contraction of the UO2 lattice parameter was observed, as well as enlargement of grain size with increasing chromium content up to 4900 ppm Cr2O3. SEM indicated Cr incorporation within the matrix and the formation of chromium oxide precipitates throughout the microstructure at high Cr concentrations. Evaluation of thermophysical properties of Cr-doped UO2 pellets were conducted up to 1200 °C to illustrate their evolution with increased dopant concentration and microstructural changes. The results show that grain size is maximized at 52 μm with Cr2O3 concentration equal to 4900 ppm; however, grain size decreases at higher Cr2O3 concentrations. No significant changes were observed in specific heat capacity, linear thermal expansion, and coefficient of thermal expansion compared to undoped UO2. The thermal conductivity also decreased through the incorporation of Cr2O3 dopants above 750 ppm and is shown to be ∼15 % lower than reported UO2 values.

Synthesis, characterization and properties of Cr-doped ZnO nanoparticles via a facile solvothermal route

Cr-doped ZnO ([Formula: see text]–0.08) nanoparticles are synthesized using the microwave solvothermal irradiation technique. The final product is calcinated at 450∘C and the nanostructure of the material is investigated using various techniques. In structural studies, XRD analysis shows that the hexagonal wurtzite structure of ZnO is present in the standard JCPDS card. FESEM spectrum reveals the hexagonal shape of the synthesized samples and EDS provides information on the qualitative composition of the nanoparticles. Optical absorbance images show exciton peaks in the UV region, which can be attributed to Cr incorporation into the ZnO lattice, and the optical energy bandgap values are calculated using the tauc plot method. Photoluminescence (PL) emission spectra are measured using PL spectroscopy. Interestingly, vibrating sample magnetometry (VSM) reveals enhancements in the magnetic properties in M–H loops and it is widely used for biological applications like antibacterial activity.

Development of Sub‐Band in Spray‐Deposited Cr‐Substituted Chalcopyrite Thin Films for Advancing Solar Cell Efficiency

Designing effective strategies for mitigating energy crisis highlights a research gap in current solar cell technologies. This study explores the inherent physicochemical properties of thin films composed of copper gallium sulfide telluride (CuGa1−xCrx(S,Te)2) with chromium substitution, prepared through the chemical spray pyrolysis technique. The investigation showcases how the concept of intermediate band structuring contributes to enhancing solar cell efficiency. This enhancement can be attributed to the remarkable mobility (from 1.80 to 5.48 cm2 V−1 s−1) and conductivity (from 1.00 to 6.06 S cm−1) exhibited by pure and 0.1 chromium thin films, respectively. Notably, the Cr‐0.1‐substituted CGST film displays maximum photoresponsivity of 0.624 AW−1, an external quantum efficiency of 145%, and a detectivity of 2.37E10. The fabricated solar cell is subjected to theoretical simulation using solar cell capacitance simulator‐1D software, revealing an upward trend in efficiency from 7.13% to 11.23% with increasing Cr substitution from 0.025 to 0.1. This efficiency improvement can be ascribed to the reduction in bandgap (from 2.40 to 1.72 eV) and the creation of a sub‐band in CGST due to Cr incorporation, as substantiated by UV–vis and NIR spectroscopy. These outcomes suggest that Cr‐0.1‐substituted CGST holds promise as a potential thin film absorber material in solar photovoltaics.

Adjusting the Effects of Cr3+ Doping on Structural, Dielectric, Antimicrobial Properties of Delafossite SrCuO2 Nanoparticle

SrCu(1−x) Cr x O2 nanoparticles (x = 0.0, 0.6, 1.2, and 1.8) nanoparticles were synthesized using sol-gel processing and subjected to calcination at 650 °C. The investigation delved into the influence of varying chromium concentrations on the structural, FTIR, electrical, and antimicrobial characteristics. The microstructure of the SrCu(1−x)Cr x O2 nanoparticles (x = 0.0, 0.6, 1.2, and 1.8) nanoparticles were analyzed through X-ray diffraction and transmission electron microscopy. Additionally, changes in chemical bonds were observed as the Cr content increased. The dielectric parameters exhibit an increase with higher Cr ratios. Additionally, there is a decrease in these parameters as the frequency rises, which could be attributed to the mobility of charged particles within the SrCu(1−x)Cr x O2 nanostructure. Our investigation underscores the significant role of Cr incorporation in influencing both the dielectric properties and antimicrobial activity of Cr, emphasizing its relevance for diverse applications.

Effect of Cr addition on the microstructure evolution, precipitation behavior and properties of Cu–Ag alloy

This investigation systematically explores the impact of minor Cr additions on the microstructural evolution, precipitation kinetics, mechanical properties, and electrical properties of Cu–Ag alloys, with a specific focus on Cu–6 %Ag-(0.4 %Cr). The alloys underwent casting through a vacuum induction furnace, followed by meticulous treatments involving solution heat and aging at varied temperatures and durations. Results indicate a significant improvement in the mechanical properties of Cu–Ag alloy upon Cr addition, with only a slight reduction in electrical conductivity. As per differential scanning calorimetry (DSC) measurements, the activation energy for continuous precipitation in the Cu–Ag–Cr ternary alloy is slightly higher than that in Cu–Ag. However, Cu–Ag–Cr lacks peaks corresponding to the discontinuous phase. Microstructural analysis unveils that Cr incorporation suppresses the discontinuous precipitation of Ag, fostering continuous precipitation during aging. Moreover, both micro-sized and nano-sized Cr particles were detected in the Cu–Ag–Cr alloy, contributing to the formation of finely spaced continuous Ag precipitates and fine Cr precipitates. This intricate microstructure imparts higher hardness and strength to the alloy compared to Cu–Ag. Specifically, following aging treatment at 450 °C for 2 h, the Cu–6 %Ag-0.4 %Cr alloy exhibited a remarkable increase of 76.1 % in hardness, 43.6 % in strength, and a moderate decrease of 15.8 % in conductivity.