Crystal Planes Research Articles

Bifunctional electrolyte additive enabling long cycle life of vanadium-based cathode aqueous zinc ion batteries

Aqueous zinc ion batteries have received extensive attention due to their many advantages, but they still face problems such as dendrite growth and interface reaction of Zn anode and collapse of vanadium-based cathode structure. Here, a bifunctional electrolyte additive Methionine (MET) is proposed, which exhibits a unique role in inducing uniform deposition of zinc anode and inhibiting the failure of vanadium-based cathode materials. MET affects the solvated structure of the electrolyte to inhibit water activity and reduce HER and other related parasitic reactions. At the same time, it regulates the flux of Zn2+, improves the deposition kinetics of Zn2+ on the zinc anode side, and induces the preferential growth of the Zn (1 0 1) crystal plane to promote ordered Zn deposition. In particular, MET can in-situ generate a CEI containing such as ZnF2 on the surface of the vanadium-based cathode to inhibit the failure of the vanadium-based cathode, while adjusting the surface electronic state and Zn2+ diffusion behavior, and reducing the structural damage of the vanadium-based cathode caused by the Zn2+ intercalation process by inducing a strengthened surface pseudocapacitive reaction. Compared with the bare electrolyte, the capacity retention rate of the K2V8O21||Zn full-cell with OTF-M50 electrolyte increased from 10.2 % to 99.8 % after 800 cycles at a low current density of 1 A/g. Therefore, MET exhibits considerable application prospects as a bifunctional additive that can improve the stability of vanadium-based cathode and promote the stable deposition of zinc anode.

Activation of iridium site based on IrO2 catalysts towards highly stable PEM water electrolyzer

The exploitation of anode electrocatalysts with high activity and stability remains an enormous challenge in proton exchange membrane (PEM) water electrolyzer. Here we doped Mn to activate Ir site in IrO2 through the molten salt sealing method, and the optimized Mn0.1Ir0.9O2 exhibited superior OER performance. Mn doping optimized the electronic structure and dominant crystal planes of IrO2, as evidenced by our complementary characterizations. Impressively, the Mn0.1Ir0.9O2 exhibits superior performance in the PEM water electrolyzer, only requiring 1.79 V to attain 1 A cm−2 and offering long-term stability over 1200 h (attenuated only 17.5 μV h−1 compared to 1.27 mV/h for the original sample). DFT calculation shows Mn doping could activate Ir site, thus reducing the energy barrier of the rate-determining step for promoting OER. This work provides a strategy to design high-tolerance catalysts for the PEM water electrolyzer in actual working conditions.

Unveiling the interface characteristics of diamond/Al interface: First-principles calculations and experiments

In this work, both first-principles calculation and experiment results revealed different interface characteristics of (111) and (100) diamond/Al interfaces. Tensile simulations were applied to examine the fracture behavior of diamond(111)/Al(111), diamond(100)/Al(111), and diamond(100)/Al4C3(003) interfaces. The results demonstrate that the work of adhesion and the tendency for Al-C bond formation are significantly greater at the diamond(100)/Al(111) compared to the diamond(111)/Al(111) interface. The growth morphology arising from reactions between Al and various diamond crystal planes is closely linked to the distinct surface characteristics of the diamond. The diamond(100)/Al4C3(003)-C terminal interface shows the highest work of adhesion due to the synergistic effects of C–C and Al-C bonding, as well as the reconstruction of diamond C atoms. During tensile calculation, multilayer relaxation occurred on the Al4C3(003) side for diamond(100)/Al4C3(003)-C terminal interface, with the highest ultimate tensile strength. While the Al atoms near the diamond(111)/Al(111) interface undergoing a clean, cohesive fracture at a tensile strain of 16 %, making it the weakest points prone to failure. The theoretical tensile strength of the diamond(100)/Al4C3(003)-C terminal interface is about 2.5 times that of the diamond(111)/Al(111) interface. Our work unveils the underlying crystal orientation-dependent growth of Al4C3 and the fracture mechanism of diamond/Al by first-principles calculations and experiments.

Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

AbstractCollapsing and degradation of active materials caused by the electrode/electrolyte interface instability in aqueous batteries are one of the main obstacles that mitigate the capacity. Herein by reversing the notorious side reactions include the loss and dissolution of electrode materials, as we applied Ostwald ripening (OR) in the electrochemical cycling of a copper hexacyanoferrate electrode in a hydronium‐ion batteries, the dissolved Cu and Fe ions undergo a crystallization process that creates a stable interface layer of cross‐linked cubes on the electrode surface. The layer exposed the low‐index crystal planes (100) and (110) through OR‐induced electrode particle growth, supplemented by vacancy–ordered (100) superlattices that facilitated ion migration. Our design stabilized the electrode–electrolyte interface considerably, achieving a cycle life of one million cycles with capacity retention of 91.6 %, and a capacity retention of 91.7 % after 3000 cycles for a full battery.

Ostwald-Ripening Induced Interfacial Protection Layer Boosts 1,000,000-Cycled Hydronium-Ion Battery.

Collapsing and degradation of active materials caused by the electrode/electrolyte interface instability in aqueous batteries are one of the main obstacles that mitigate the capacity. Herein by reversing the notorious side reactions include the loss and dissolution of electrode materials, as we applied Ostwald ripening (OR) in the electrochemical cycling of a copper hexacyanoferrate electrode in a hydronium-ion batteries, the dissolved Cu and Fe ions undergo a crystallization process that creates a stable interface layer of cross-linked cubes on the electrode surface. The layer exposed the low-index crystal planes (100) and (110) through OR-induced electrode particle growth, supplemented by vacancy-ordered (100) superlattices that facilitated ion migration. Our design stabilized the electrode-electrolyte interface considerably, achieving a cycle life of one million cycles with capacity retention of 91.6 %, and a capacity retention of 91.7 % after 3000 cycles for a full battery.

Zincophilic Sites Enriched Hydrogen-bonded Organic Framework as Multifunctional Regulating Interfacial Layers for Stable Zinc Metal Batteries.

To construct an efficient regulating layer for Zn anodes that can simultaneously address the issues of dendritic growth and side reactions is highly demanded for stable zinc metal batteries (ZMBs). Herein, we fabricate a hydrogen-bonded organic framework (HOF) enriched with zincophilic sites as a multifunctional layer to regulate Zn anodes with controlled spatial ion flux and stable interfacial chemistry (MA-BTA@Zn). The framework with abundant H-bonds helps capture H2O and remove the solvated shells on [Zn(H2O)6]2+, leading to suppressed side reactions. The HOF layer also helps form electrolyte-philic surfaces and expose Zn (002) crystal planes which benefit for rapid conduction and uniform deposition of Zn2+, and weakened sides reactions. Additionally, the electrochemically active zincophilic sites (C=O, -NH2 and triazine groups) favor the targeted guidance and penetration of Zn2+ and provide advantageous sites for uniform Zn deposition. High Young's modulus of the HOF layer further contributes to a high interfacial flexibility and stability against Zn plating-associated stress. The MA-BTA@Zn symmetric cells thereby obtain a substantially extended battery life over 1000 h at 4 mA cm-2. The MA-BTA@Zn||Cu half-cell demonstrates a highly reversible Zn stripping/plating process over 1500 cycles with impressive average Coulombic efficiency (CE) of 99.5% at 10 mA cm-2.

Zincophilic Sites Enriched Hydrogen‐Bonded Organic Framework as Multifunctional Regulating Interfacial Layers for Stable Zinc Metal Batteries

AbstractTo construct an efficient regulating layer for Zn anodes that can simultaneously address the issues of dendritic growth and side reactions is highly demanded for stable zinc metal batteries (ZMBs). Herein, we fabricate a hydrogen‐bonded organic framework (HOF) enriched with zincophilic sites as a multifunctional layer to regulate Zn anodes with controlled spatial ion flux and stable interfacial chemistry (MA‐BTA@Zn). The framework with abundant H‐bonds helps capture H2O and remove the solvated shells on [Zn(H2O)6]2+, leading to suppressed side reactions. The HOF layer also helps form electrolyte‐philic surfaces and expose Zn (002) crystal planes which benefit for rapid conduction and uniform deposition of Zn2+, and weakened sides reactions. Additionally, the electrochemically active zincophilic sites (C=O, −NH2 and triazine groups) favor the targeted guidance and penetration of Zn2+ and provide advantageous sites for uniform Zn deposition. High Young's modulus of the HOF layer further contributes to a high interfacial flexibility and stability against Zn plating‐associated stress. The MA‐BTA@Zn symmetric cells thereby obtain a substantially extended battery life over 1000 h at 4 mA cm−2. The MA‐BTA@Zn||Cu half‐cell demonstrates a highly reversible Zn stripping/plating process over 1500 cycles with impressive average Coulombic efficiency (CE) of 99.5 % at 10 mA cm−2.

Effects of heat input on microstructure evolution and corrosion resistance of underwater laser cladding high-strength low-alloy steel coating

The effects of heat input on the microstructure evolution and corrosion resistance of the high-strength low-alloy (HSLA) steel coating obtained by wire-feed underwater laser cladding were studied. Optical digital microscope, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscope (TEM), electron back-scattered diffraction (EBSD), electrochemical tests, laser microscope and other characterization methods were used. As the heat input increased, the smoothness of the underwater cladding coating improved, with little changes in elemental distribution and phase composition. However, the content of acicular ferrite increased, while the amounts of lath bainite, lath martensite, and granular bainite decreased. As the heat input increased from 0.4 to 0.55 kJ/mm, the grain size increased from 25.3 to 55.9 μm, the proportion of low-angle grain boundaries rose from 61.3 % to 69.1 %, and the texture intensity of the (110) crystal plane increased from 16.22 to 23.83. Meanwhile, the dislocation density decreased from 4.9 × 1014 to 4.1 × 1014 m−2. These changes enhanced the corrosion resistance of underwater coating. As the heat input increased from 0.4 to 0.55 kJ/mm, the corrosion current density decreased from 2.13 × 10−5 to 3.35 × 10−6 A/cm2, and the corrosion potential increased from −0.823 to −0.529 V. Additionally, the depth-to-width ratio of the corrosion pits decreased from 0.255 to 0.053. This study laid the foundation for high-quality in-situ underwater repairs of ships and submarines made of high-strength steel.

Evolution from micropinned to polymeric alloy structure of XLPE‐PS: Improving electrical properties and mechanism

AbstractThis research investigates the transition from a micropinned to a polymeric alloy structure in crosslinked‐polyethylene‐polystyrene (XLPE‐PS). Incorporating 2 wt% 10 μm PS particles into low‐density polyethylene (LDPE) and crosslinking with 2 wt% dicumyl peroxide (DCP) forms XLPE‐PS structures. The polymeric alloy structure, formed at 220°C extrusion, contrasts with the micropinned formed at 150°C. Morphological, thermo‐structural, chemical, and crystal properties are examined to understand their impact on electrical properties and charge transport mechanisms. Results indicate that the polymeric alloy effectively resolves void/crack issues, whereas the micropinned exhibits phase separation. Both structures exhibit a benzene‐crosslinked network, and variations in these structures lead to significant changes in thermo‐structural, chemical, and crystalline properties. The polymeric alloy XLPE‐PS shifts the polyethylene (PE) hkl crystal planes, confirming phase shift and optimal alloying. The structural alterations reveal deeper traps and higher densities in the polymeric alloy XLPE‐PS, leading to significantly improved electrical properties, including reduced DC conductivity by up to 1.3 and 0.7 decades at 30 and 90°C, and increased DC breakdown strength by up to 40.34% and 16.17% at 30 and 90°C, respectively, compared with micropinned XLPE‐PS. This research offers insights into stable high‐voltage insulation development.

Fe2O3 Nanoflakes - WS2 Nanosheets Heterojunctions for Multi-Fold Enhancement in Photoelectrochemical Solar Energy Conversion.

Fe2O3-based photoanodes show great potential in photoelectrochemical water splitting due to their excellent stability, moderate band gap, and abundance. However, a short hole diffusion length limits its photocurrent density. Here, a multi-fold enhancement in photocurrent density from Fe2O3 nanoflakes - WS2 nanosheets heterojunction is reported. The heterojunction exhibits a synergistic photocurrent density of 0.52mA cm-2 at 1.3V (versus RHE) under AM 1.5G simulated sunlight, which is 2.23 times higher than pristine Fe2O3 nanoflakes. The Mott-Schottky and Nyquist plots indicate a higher charge density with lower charge transfer resistance at the semiconductor-electrolyte junction. The density functional theory (DFT) -based first-principles calculations are performed by designing a heterostructure between Fe2O3(110) and WS2(001) similar to the experimentally found arrangement of crystal planes. Free energy analysis and relative band extrema positions, obtained from DFT calculations and valence band spectroscopy, indicate the formation of type II heterojunction with partial oxygen terminated surface of Fe2O3. The type-II band alignment with a charge transfer of 4.8 × 10-4 e per interfacial WS2 to Fe2O3, helps in easy separation of photogenerated charges. The work establishes both an experimental design and a theoretical framework of highly crystalline nanoflakes-nanosheet heterojunctions for efficient photoelectrochemical solar energy conversion.

Coupling Manipulation of Interfacial Chemistry and Coordination Structure in Vanadium Oxides Enables Rapid Magnesium Ion Diffusion Kinetics

AbstractRechargeable magnesium batteries (RMBs) are a highly promising energy storage system due to their high volumetric capacity and intrinsic safety. However, the practical development of RMBs is hindered by the sluggish Mg2+ diffusion kinetics, including at the cathode‐electrolyte interface (CEI) and within the cathode bulk. Herein, we propose an efficient strategy to manipulate the interfacial chemistry and coordination structure in oligolayered V2O5 (L−V2O5) for achieving rapid Mg2+ diffusion kinetics. In terms of the interfacial chemistry, the specific exposed crystal planes in L−V2O5 possess strong electron donating ability, which helps to promote the degradation dynamics of C−F/C−S bonds in the electrolyte, thereby establishing the inorganic‐organic interlocking CEI layer for rapid Mg2+ diffusion. In terms of the coordination structure, the straightened V−O structure in L−V2O5 provides efficient ions diffusion path for accelerating Mg2+ diffusion in the cathode. As a result, the L−V2O5 delivers a high reversible capacity (355.3 mA h g−1 at 0.1 A g−1) and an excellent rate capability (161 mAh g−1 at 1 A g−1). Impressively, the interdigital micro‐RMBs is firstly assembled, exhibiting excellent flexibility and practicability. This work gives deeper insights into the interface and interior ions diffusion for developing high‐kinetics RMBs.

Coupling Manipulation of Interfacial Chemistry and Coordination Structure in Vanadium Oxides Enables Rapid Magnesium Ion Diffusion Kinetics.

Rechargeable magnesium batteries (RMBs) are a highly promising energy storage system due to their high volumetric capacity and intrinsic safety. However, the practical development of RMBs is hindered by the sluggish Mg2+ diffusion kinetics, including at the cathode-electrolyte interface (CEI) and within the cathode bulk. Herein, we propose an efficient strategy to manipulate the interfacial chemistry and coordination structure in oligolayered V2O5 (L-V2O5) for achieving rapid Mg2+ diffusion kinetics. In terms of the interfacial chemistry, the specific exposed crystal planes in L-V2O5 possess strong electron donating ability, which helps to promote the degradation dynamics of C-F/C-S bonds in the electrolyte, thereby establishing the inorganic-organic interlocking CEI layer for rapid Mg2+ diffusion. In terms of the coordination structure, the straightened V-O structure in L-V2O5 provides efficient ions diffusion path for accelerating Mg2+ diffusion in the cathode. As a result, the L-V2O5 delivers a high reversible capacity (355.3 mA h g-1 at 0.1 A g-1) and an excellent rate capability (161 mAh g-1 at 1 A g-1). Impressively, the interdigital micro-RMBs is firstly assembled, exhibiting excellent flexibility and practicability. This work gives deeper insights into the interface and interior ions diffusion for developing high-kinetics RMBs.

Morphology and crystal–plane dependent catalytic activity of α-Fe2O3 for NH3-SCR de-NOx: Experimental and DFT study

Three kinds of α-Fe2O3 catalysts, each having a distinct morphology and crystal planes, were synthesized and applied for NH3-SCR reaction. The morphology and crystal-plane effects for the activity of α-Fe2O3 were investigated by a combined study of experiment and density functional theory. The experiment findings reveal that the α-Fe2O3-S, α-Fe2O3-R, and α-Fe2O3-C display the shuttle (predominantly exposed (110) and (012) crystal planes), rod (predominantly exposed (110), (104), and (012) crystal planes), and cube (only exposed (104) crystal plane) shapes, respectively. Furthermore, the α-Fe2O3-S yields the best catalytic performance because of its moderate surface acidity, the best redox capacity, and the highest contents of surface Fe3+ and chemisorbed oxygen, which may result from the morphology and crystal plane effects. Additionally, the activity of different crystal planes is significantly different. The NO and NH3 are more apt to be adsorbed on the (110) and (012) surfaces and O2 dissociation is more likely to happen on the (110) surface. Besides these, the (110) surface owns the lowest energy barrier to the decomposition of intermediate NH2NO. All of the mentioned above collectively enhance the efficiency of the SCR process. Finally, the (110) and (012) surfaces facilitate the rapid SCR process, while the (104) surface is the most difficult. The α-Fe2O3-S predominately exposes high activity of (110) and (012) surfaces, therefore, it can yield the highest catalytic activity.

Physically crosslinked hydrogel based on silver nanowires with a discontinuous rigid framework for robust, sensitive, antibacterial, and biocompatible flexible sensors

Conductive hydrogels as flexible sensors fulfill the essential requirements of realtime monitoring and sensitive transmission in the fields of human-machine interaction. However, it is still a great challenge to integrate satisfying mechanical properties, sensitivity, antibacterial efficacy, and biocompatibility into one hydrogel sensor while ensuring a precise output signal. Herein, ultrathin silver nanowires (AgNWs) were prepared by controlling the growth of Ag atoms in (111) crystal planes within the Ethylene Glycol-Polyvinylpyrrolidone (EG-PVP) reduction system. Then, multifunctional hydrogel (SA-SH-AgNWs/PVA) was developed by physically crosslinking polyvinyl alcohol (PVA) and thiol-modified sodium alginate (SA-SH) in AgNWs aqueous solution through freeze-thaw circulation and Ca2+ crosslink. The AgNWs were adsorbed onto sodium alginate (SA) chains through electrostatic adsorption with thiol groups (-SH), forming a discontinuous rigid framework structure with a 278 % increase in tensile strength. The uniform dispersion of AgNWs within the hydrogel offers good sensing performance: gauge factor (GF) of 2.40 and sensitivity (S) of 3.24 × 10−2 kPa−1, and satisfying antibacterial abilities. What’s more, the obtained hydrogel can serve as stretching or compressing sensors to detect tiny yet intricate changes of human bodies. Therefore, the hydrogel is a great inspiration for the development of portable, intelligent, and highly flexible sensors.

Unveiling the temperature-dependent deformation mechanisms of single crystal gallium nitride in nanoscratching

The surface grinding process of single crystal gallium nitride (GaN) is intricate, and localized high temperature generated during interactions between the workpiece and the abrasives on grinding wheel is inevitable. Elevated temperatures significantly affect the deformation mechanisms of GaN, which remains inadequately elucidated. In this study, nanoscratching experiments were systematically conducted on the (0001) plane of GaN single crystal across a temperature range up to 500 ℃, and the resultant deformation patterns were thoroughly characterized. The results indicate that temperature elevation delays the brittle-to-ductile transitions in GaN and enhance its anisotropy. Additionally, GaN exhibits increased plasticity as temperature rises, leading to distinct scratch-induced subsurface deformation patterns at varying temperatures: at room temperature, the thickness of the subsurface damaged layer is primarily influenced by the penetration depth of cross slips, whereas at 500 ℃, basal slipping predominantly defines the thickness of the subsurface damaged layer. The plastic deformation patterns at both room temperature and 500 ℃ mainly involve phase transition, polycrystal formation, slips, stacking faults, dislocations and lattice distortions. The discrepancies in deformations at varying temperatures were thoroughly investigated by transmission electron microscopy and molecular dynamics simulations, and the underlying mechanisms were elucidated.

Individual-Ion Addressing and Readout in a Penning Trap.

We implement individual addressing and readout of ions in a rigidly rotating planar crystal in a compact, permanent magnet Penning trap. The crystal of ^{40}Ca^{+} is trapped and stabilized without defects via a rotating triangular potential. The trapped ion fluorescence is detected in the rotating frame for parallel readout. The qubit is encoded in the metastable D_{5/2} manifold enabling the use of high-power near-infrared laser systems for qubit operations. Addressed σ_{z} operations are realized with a focused ac Stark shifting laser beam. We demonstrate addressing of ions near the center of the crystal and at large radii. Simulations show that the current addressing operation fidelity is limited to ∼97% by the ion's thermal extent for the in-plane modes near the Doppler limit, but this could be improved to infidelities <10^{-3} with sub-Doppler cooling. The techniques demonstrated in this Letter complete the set of operations for quantum simulation with the platform.

Crystal plane engineering-tailored Co-Ni bimetallic sites in CoNiO2 to achieve efficient photocatalytic CO2 reduction

Aligning the atomic structure of catalyst by the crystal-plane engineering is an effective strategy to enhance the photocatalytic activity. In this paper, the CoNiO2 nanosheets (NSs) with (200) and nanorods (NRs) with (111) crystal planes were successfully prepared through a simple hydrothermal method for CO2 photoreduction. The experimental results indicated that the CNO NRs had excellent CO2 photoreduction performance. The CO and CH4 yields over CNO NRs were about 48.66 and 5.84 μmol·g−1·h−1, which were about 2.62 and 2.61 times stronger than that of CNO NSs. Moreover, it was also about 10.70 and 6.25 times as good as the TiO2 commercial powder, respectively. Experimental and theoretical calculations demonstrated that the Co-Ni bimetallic sites on the (111) crystal plane of CNO NRs can effectively enhance the CO2 adsorption and activation ability compared with the single Ni site on the (200) crystal plane of CNO NSs. Besides, the energy barrier required for the development of the critical intermediate *COOH from *CO2 was greatly reduced on the Co-Ni bimetallic sites, thereby improving the CO2 photoreduction activity. The reaction paths were inferred by in-situ FTIR and 13C isotope tracer techniques, and finally a potential enhancement mechanism of the crystal plane engineering induces bimetallic sites to promote CO2 adsorption and activation process has been proposed.

Effect of chemical bonding and relative density on microwave dielectric properties of LiInW2O8 ceramics

To meet the demands of the growing field of electronic communications, LiInW2O8 ceramics with low dielectric loss (high Q×f) and low dielectric constant (εr) are prepared by a solid phase reaction method. X-ray diffractometry reveals a scheelite single-phase structure for the prepared ceramics. Compared with the standard LiInW2O8, the as-prepared LiInW2O8 has a higher relative diffraction intensity for the (200) crystal plane, indicating an anisotropic growth phenomenon in the present case. Raman spectroscopy and calculations of the P-V-L complex chemical bonding theory show that W-O bonding is a key factor affecting the dielectric properties of LiInW2O8 ceramics. Furthermore, excellent microwave dielectric properties with εr ≈ 14.2, Q×f ≈ 63000 GHz, and τf ≈ −28 ppm/℃ are obtained by sintering the ceramic at 1025°C.

The Introduction of a BaTiO3 Polarized Coating as an Interface Modification Strategy for Zinc-Ion Batteries: A Theoretical Study.

Aqueous zinc-ion batteries (AZIBs) have become a promising and cost-effective alternative to lithium-ion batteries due to their low cost, high energy, and high safety. However, dendrite growth, hydrogen evolution reactions (HERs), and corrosion significantly restrict the performance and scalability of AZIBs. We propose the introduction of a BaTiO3 (BTO) piezoelectric polarized coating as an interface modification strategy for ZIBs. The low surface energy of the BTO (110) crystal plane ensures its thermodynamic preference during crystal growth in experimental processes and exhibits very low reactivity toward oxidation and corrosion. Calculations of interlayer coupling mechanisms reveal a stable junction between BTO (110) and Zn (002), ensuring system stability. Furthermore, the BTO (110) coating also effectively inhibits HERs. Diffusion kinetics studies of Zn ions demonstrate that BTO effectively suppresses the dendrite growth of Zn due to its piezoelectric effect, ensuring uniform zinc deposition. Our work proposes the introduction of a piezoelectric material coating into AZIBs for interface modification, which provides an important theoretical perspective for the mechanism of inhibiting dendrite growth and side reactions in AZIBs.

Optimization, imaging and LHE analysis of magnesium oxide nanoparticles synthesized with carambola extract as natural dye sensitizer

This work explores the enhancement of dye-sensitized solar cells (DSSCs) by using magnesium oxide nanoparticles (MgO NPs) that have been green-synthesized, with carambola extract acting as a natural dye sensitizer. Green synthesis minimizes the negative effects of traditional synthesis methods on the environment by providing a sustainable and ecologically friendly way to produce MgO NPs. To increase their effectiveness in DSSC applications, the synthesized nanoparticles underwent optimization. The morphology and size distribution of MgO NPs were characterized by scanning electron microscopy (SEM), which revealed spherical forms with a consistent size distribution. The crystalline nature of the MgO NPs was verified by X-ray diffraction (XRD), which revealed distinctive peaks that correspond to the bulk MgO crystal planes. A band gap of 3.5 eV, appropriate for UV region absorption, was found using UV–visible spectroscopy. FT-IR (Fourier-transform infrared) spectroscopy revealed information about their molecular compositions. Positive electronic characteristics, such as a negative total energy change (ΔE_T) and a high electrophilicity index (ω), which indicates effective charge transfer, were found through computational analysis. The light harvesting efficiency (LHE) value of 0.00459 signifies optimal light absorption capability by the dye molecule. The outcomes show that MgO NPs that have undergone green synthesis have the potential to be efficient and stable sensitizers for DSSCs. In addition to highlighting the significance of green synthesis techniques in nanomaterial research for renewable energy applications, this work advances the development of efficient and sustainable solar energy systems.