The properties of Sweet Sorghum Syrup Produced by Combined Vacuum Falling Film and Rotary Evaporation

The combination of Vacuum Falling Film Evaporator(FFE) and Rotary Evaporator (RE) was conducted in producing sweet sorghum syrup. The aim of this research was to evaluate the performance of single FFE and combined FFE-RE on sorghum syrup concentration. Single FFE was studied at the temperature of 70, 80, and 90°C. The best single FFE treatment was continued by RE at 60, 70, and 80°C. Sweet sorghum that were concentrated using single FFE(90°C) and combined FFE(90°C)-RE(80°C) had the highest Total Soluble Solid(TSS) of 44.2°Brix and 87.53°Brix, also the acceptable lightness(L*) of 30.13 and 25.83 respectively. That combined FFE-RE produced sorghum syrup had the highest overall Hedonic score 3.34 within the taste parameter value of 2.89; color of 3,75; aroma of 3,29; and texture of 3.42. It was also accomplished with the redness(a*) of -2.11, yellowness(b*) of 5.13, turbidity of 387.66 NTU, viscosity of 2036.67cP, and reducing sugar of 52.54%

Understanding H2 evolution electrochemistry to minimize solvated water impact on zinc anode performance

Published online: 20 September 2022H2 evolution is the reason for poor reversibility and limited cycle stability with Zn metal anodes, and impedes practical application in aqueous zinc ion batteries (AZIB). Here we demonstrate for the first time, using combined gas chromatography experiment and computation, that H2 evolution primarily originates from solvated water, rather than free water without interaction with Zn2+ . We evidence, using linear sweep voltammetry (LSV) in salt electrolytes that H2 evolution occurs at a more negative potential than zinc reduction because of high overpotential against H2 evolution on Zn metal. We test our hypothesis and confirm, using glycine additive to reduce solvated water, that H2 evolution and "parasitic" side reactions are suppressed on the Zn anode. We evidence that this electrolyte additive suppresses H2 evolution, reduces corrosion and gives a uniform Zn deposition in Zn|Zn and Zn|Cu cells when compared with bare ZnSO4 electrolyte. We demonstrate Zn|PANI (highly conductive polyaniline) full cells exhibit boosted electrochemical performance in 1 M ZnSO4 -3 M glycine electrolyte and, a high reversible capacity of 100 mAh g-1 in a practical Zn|PANI pouch cell. We conclude that this new understanding of electrochemistry of H2 evolution can be used for design of relatively low-cost and safe AZIB for practical large-scale energy storage. Findings will be of immediate benefit in electrolyte design for high performance rechargeable batteries and therefore of wide interest to researchers and manufacturers. This article is protected by copyright. All rights reserved.Fuhua Yang, Jodie A. Yuwono, Junnan Hao, Jun Long, Libei Yuan, Yanyan Wang, Sailin Liu, Yameng Fan, Shiyong Zhao, Kenneth Davey, and Zaiping Gu

Tuning the Coordination Structure of Cu-N-C Single Atom Catalysts for Simultaneous Electrochemical Reduction of CO2 and NO3 - to Urea

Closing both the carbon and nitrogen loops is a critical venture to support the establishment of the circular, net-zero carbon economy. Although single atom catalysts (SACs) have gained interest for the electrochemical reduction reactions of both carbon dioxide (CO₂RR) and nitrate (NO₃RR), the structure–activity relationship for Cu SAC coordination for these reactions remains unclear and should be explored such that a fundamental understanding is developed. To this end, the role of the Cu coordination structure is investigated in dictating the activity and selectivity for the CO₂RR and NO3RR. In agreement with the density functional theory calculations, it is revealed that Cu-N₄ sites exhibit higher intrinsic activity toward the CO₂RR, whilst both Cu-N₄ and Cu-N₄−x-Cx sites are active toward the NO3RR. Leveraging these findings, CO₂RR and NO₃RR are coupled for the formation of urea on Cu SACs, revealing the importance of *COOH binding as a critical parameter determining the catalytic activity for urea production. To the best of the authors’ knowledge, this is the first report employing SACs for electrochemical urea synthesis from CO₂RR and NO₃RR, which achieves a Faradaic efficiency of 28% for urea production with a current density of −27 mA cm–2 at −0.9 V versus the reversible hydrogen electrode.Josh Leverett, Thanh Tran-Phu, Jodie A. Yuwono, Priyank Kumar, Changmin Kim, Qingfeng Zhai, Chen Han, Jiangtao Qu, Julie Cairney, Alexandr N. Simonov, Rosalie K. Hocking, Liming Dai, Rahman Daiyan, and Rose Ama

Unraveling the structure-activity-selectivity relationships in furfuryl alcohol photoreforming to H2 and hydrofuroin over ZnxIn2S3+x photocatalysts

ZnxIn2S3+x has emerged as a promising candidate for alcohol photoreforming based on C-H activation and C-C coupling. However, the underlying structure-activity-selectivity relationships remain unclear. Here we report on ZnxIn2S3+x with varying Zn:In:S ratios for visible-light-driven furfuryl alcohol reforming into H2 and hydrofuroin, a jet fuel precursor, via C-H activation and C-C coupling. S-• radicals are directly identified as the catalytically active sites responsible for C-H activation in furfuryl alcohol, promoting selectivity toward H2 and hydrofuroin. The optimum ZnxIn2S3+x activity derives from a trade-off between enhanced carrier dynamics and diminished visible light absorption as the x value in ZnxIn2S3+x increases. Further, a higher Zn-S:In-S layer ratio prolongs the S-• lifetime in the Zn-S layer, promoting C-H activation and delivering a higher C-C coupling product selectivity. The findings represent a step toward further establishing sulfide-based photocatalysts for sustainable H2 production via organic photoreforming.Denny Gunawan, Jodie A. Yuwono, Priyank V. Kumar, Akasha Kaleem, Michael P. Nielsen, Murad J.Y. Tayebjee, Louis Oppong-Antwi, Haotian Wen, Inga Kuschnerus, Shery L.Y. Chang, Yu Wang, Rosalie K. Hocking, Ting-Shan Chan, Cui Ying Toe, Jason Scott, Rose Ama

Atomistic Insights into Lithium Storage Mechanisms in Anatase, Rutile, and Amorphous TiO2 Electrodes

Density functional theory calculations were used to investigate the phase transformations of LixTiO2 (at 0 ≤ x ≤ 1), solidstate Li+ diffusion, and interfacial charge-transfer reactions in both crystalline and amorphous forms of TiO2. It is shown that in contrast to crystalline TiO2 polymorphs, the energy barrier to Li+ diffusion in amorphous TiO2 decreases with increasing mole fraction of Li+ due to the changes of chemical species pair interactions following the progressive filling of low-energy Li+ trapping sites. Sites with longer Li−Ti and Li−O interactions exhibit lower Li+ insertion energies and higher migration energy barriers. Due to its disordered atomic arrangement and increasing Li+ diffusivity at higher mole fractions, amorphous TiO2 exhibits both surface and bulk storage mechanisms. The results suggest that nanostructuring of crystalline TiO2 can increase both the rate and capacity because the capacity dependence on the bulk storage mechanism is minimized and replaced with the surface storage mechanism. These insights into Li+ storage mechanisms in different forms of TiO2 can guide the fabrication of TiO2 electrodes to maximize the capacity and rate performance in the futureJodie A. Yuwono, Patrick Burr, Conor Galvin, and Alison Lenno

Atomistic Mechanisms of Mg Insertion Reactions in Group XIV Anodes for Mg-Ion Batteries

Magnesium (Mg) metal has been widely explored as an anode material for Mg-ion batteries (MIBs) owing to its large specific capacity and dendrite-free operation. However, critical challenges, such as the formation of passivation layers during battery operation and anode− electrolyte−cathode incompatibilities, limit the practical application of Mg-metal anodes for MIBs. Motivated by the promise of group XIV elements (namely, Si, Ge, and Sn) as anodes for lithium- and sodium-ion batteries, here, we conduct systematic first-principles calculations to explore the thermodynamics and kinetics of group XIV anodes for MIBs and to identify the atomistic mechanisms of the electrochemical insertion reactions of Mg ions. We confirm the formation of amorphous MgxX phases (where X = Si, Ge, and Sn) in anodes via the breaking of the stronger X−X bonding network replaced by weaker Mg−X bonding. Mg ions have higher diffusivities in Ge and Sn anodes than in Si, resulting from weaker Ge−Ge and Sn−Sn bonding networks. In addition, we identify thermodynamic instabilities of MgxX that require a small overpotential to avoid aggregation (plating) of Mg at anode/electrolyte interfaces. Such comprehensive first-principles calculations demonstrate that amorphous Ge and crystalline Sn can be potentially effective anodes for practical applications in MIBs.Mingchao Wang, Jodie A. Yuwono, Vallabh Vasudevan, Nick Birbilis, and Nikhil V. Medheka

Understanding the enhanced rates of hydrogen evolution on dissolving magnesium

Despite the growing interest in Mg and its alloys, their use has been largely limited due to their high reactivity in aqueous environments. Improving the understanding of the basic principles of Mg corrosion represents the first step to explain and, eventually, improve the corrosion behaviour of Mg alloys. Herein an original mechanistic surface kinetic DFT model that clarifies the mechanism of anomalous HE on anodically polarised Mg is presented. In accordance with several experimental observations, this model describes anomalous HE proceeding at the regions dominated by anodic dissolution via the reaction of an Mg*H intermediate with water. The Mg*H intermediates undergo oxidation upon anodic polarisation, resulting in hydrogen evolution and Mg dissolution. Furthermore, it is revealed that increasing rates of an electrochemical cathodic reaction are possible within a dissolving anode.SF acknowledges the Spanish State Research Agency (Ministry of Science, Technology and Universities of Spain), the Spanish National Research Council (CSIC) and the European Regional Development Fund (ERDF) for the financial support under the Project MAT2015-74420-JIN (AEI/FEDER/UE). JAY acknowledges the National Computational Infrastructure (NCI) Raijin and the Pawsey Supercomputing Centre Magnus.Peer Reviewe

Ion Agglomeration and Transport in MgCl2-Based Electrolytes for Rechargeable Magnesium Batteries.

Magnesium halide salts are an exciting prospect as stable and high-performance electrolytes for rechargeable Mg batteries (RMBs). By nature of their complex equilibria, these salts exist in solution as a variety of electroactive species (EAS) in equilibrium with counterions such as AlCl₄‾. Here we investigated ion agglomeration and transport of several such EAS in MgCl₂ salts dissolved in ethereal solvents under both equilibrium and operating conditions using large-scale atomistic simulations. We found that the solute morphology is strongly characterized by the presence of clusters and is governed by the solvation structures of EAS. Specifically, the isotropic solvation of MgCl²⁺ results in the slow formation of a bulky cluster, compared with chainlike analogues observed in the Cl-containing EAS such as Mg₂Cl₃⁺, MgCl⁺, and Mg₂Cl₃⁺. We further illustrate these clusters can reduce the diffusivity of charge-carrying species in the MgCl₂-based electrolyte by at least an order of magnitude. Our findings for cluster formation, morphology, and kinetics can provide useful insight into the electrochemical reactions at the anode-electrolyte interface in RMBs.Vallabh Vasudevan, Mingchao Wang, Jodie A. Yuwono, Jacek Jasieniak, Nick Birbilis, and Nikhil V. Medheka

Aqueous Electrochemical Activity of the Mg Surface: The Role of Group 14 and 15 Microalloying Elements

Comparatively little is known about the aqueous electrochemical characteristics of magnesium (Mg) alloyed with group 14 and 15 elements. A combined analysis of theoretical and experimental studies was used to evaluate the role of such alloying elements in Mg surface reactions. The surface work function and surface hydroxylation reaction enthalpies were calculated, and the surface Pourbaix diagrams were constructed using first principles calculations. Group 14 and 15 elements exhibit the ability to restrict the water splitting and surface hydroxylation reaction upon Mg, thus providing an insight into their ability to suppress cathodic activation of Mg. Experimental studies using polarization, immersion testing, electrochemical impedance spectroscopy (EIS) and Raman spectroscopy verify a decreased electrochemical activity of Mg-0.3 Ge and Mg-0.3 Sb alloys, compared to that of pure Mg. The approaches presented here provide a means by which a metallurgical alloying can be used as a valuable mechanism for controlling Mg surface activity with beneficial implications for various applications of Mg.Jodie A. Yuwono, z Nick Birbilis, Ruiliang Liu, Qingdong Ou, Qiaoliang Bao, and Nikhil V. Medhekar

Reduced Silicon Fragmentation in Lithium Ion Battery Anodes Using Electronic Doping Strategies

Although Si anodes have the potential to achieve gravimetric capacities >3000 mA g−1 for Li ion batteries, their utility has been limited by their large volumetric expansion on lithiation and electrode fragmentation. We show that n-type doping reduces the lithiation potential of (100) Si and conclude that the Li ion insertion energy into crystalline Si increases with ntype dopant density. This allows tuning of the n-type dopant density in Si electrodes to reduce surface fragmentation and increase electrode cycle life. Using a combination of n-type doping, prelithiation at a low current density of 0.05 mA cm−2 and an areal capacity capping at 2 mAh cm−2, we show that stable cycling can be achieved at a current density of 1 mA cm−2 within the potential range of 0.01−1.5 V for at least 140 cycles using an organic electrolyte without additives. Further improvements in cyclability can be achieved by using alternative electrolytes with greater electrochemical stability at low potentials. Because of the massively reduced cost of Si wafers, heavily doped wafer-based current collectors may present an alternative to Si thin film anodes with improved adhesion between the current collector and electroactive Si surface provided that the wafers can be sufficiently thin to reduce electrode mass and volume. Alternatively, n-type doping of Si can be used to reduce fragmentation in particle-based electrodes permitting more controllable lithiation and a longer cycle life.Derwin Lau, Charles A. Hall, Sean Lim, Jodie A. Yuwono, Patrick A. Burr, Ning Song, and Alison Lenno