The oxygen reduction reaction (ORR) in neutral media is of great importance due to its potential to optimize energy generation and storage application. With the increasing urgency for sustainable and ...efficient energy solutions, comprehensively understanding and enhancing ORR performance in such media have become crucial. This review aims to shed light on this critical yet challenging area. This review encapsulates the fundamental principle of ORR and the latest breakthrough in the field of electrocatalysts, with a distinct focus on innovative synthesis strategies for creating novel, efficient, and robust electrocatalysts. A succinct evaluation of the strengths, limitations, performance, and reaction mechanism is presented. The essential findings are analyzed and their implications for future research directions. Finally, an outlook on current advances, challenges, and future research recommendations is provided. This review serves as a stepping‐stone toward harnessing the underutilizing energy potential within the extensive aquatic environment.
This comprehensive review delves into the latest breakthroughs in catalyst development for the oxygen reduction reaction in neutral media, with a distinct focus on innovative synthesis strategies employed to create novel, highly efficient, and robust electrocatalysts. The review also identifies potential areas for further innovation, serving as a valuable guide for researchers working in this field of sustainable energy research.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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•The biomass-derived compound, HMF, was electrooxidized to high-value product 2,5-diformylfuran, DFF.•Co10-aCeaOx electrocatalyst for HMF electrooxidation was first reported.•HMF ...electrooxidation to DFF with 80% selectivity in neutral conditions could be achieved.•The reaction pathway of HMF electrooxidation was proposed based on HPLC and electrochemical studies.
This study reports for the first time the use of amorphous mixed cobalt-cerium metal oxides (Co10-aCeaOx), obtained by photochemical metal-organic deposition, for 5-hydroxymethylfurfural (HMF) oxidation. The optimized Co8Ce2Ox exhibites a good electrocatalytic activity toward HMF oxidation with a current density of 2.8 mA cm−2 at 1.60 V, which is 1.4 times higher than that of pure CoOx. Operando Raman spectra reveal that the incorporation of Ce alters the electronic structure of the composite by facilitating the formation of CoOOH/CoO2, thus promoting catalytic activity. Notably, it is found that the oxidation of HMF proceeds dominantly via the oxidation of the alcohol group, followed by its subsequent oxidation in both alkaline and neutral media. Due to the stability of the aldehyde group in neutral media, high valuable 2,5-diformylfuran (DFF) with the selectivity of 60%–92% is obtained, thus open the new route for electrocatalytic DFF production.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A high-performance BiVO4 photoanode with a CoMnZn nanosheet cocatalyst was fabricated for photoelectrochemical water splitting. The cocatalyst boosted the photoelectrocatalytic activity, and ...photoanode stability.
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•BiVO4/CoMnZn-LDH photoanode is successfully fabricated by fast and economic method.•The hybrid photoanode exhibits vastly enhanced water splitting activity.•Surface recombination of photogenrated electron-hole pairs is near-complete suppressed.•The enhancing mechanism is attributed to effective utilization of photogenerated carriers.•Co, Mn and Zn present synergistic effect toward the enhanced photoelectrochemical performance.
A novel ternary hydrotalcite-like nanosheet is directly integrated onto bismuth vanadate (BiVO4) photoanode via a fast, precisely controllable and economic electrodeposition method. The CoMnZn-containing hydroxides could play multifunctional roles as an efficient cocatalyst to lower the onset potential and enhance the photocurrent and as a protection layer for bismuth vandate. The hybrid photoanode shows a much improved PEC performance compared with bare bismuth vanadate, with a photocurrent density enhancement of 170% (from 0.61 mA cm−2 to 1.06 mA cm−2) and a decrease of 280 mV in onset potential. Surface modification of photoanodes with trimetallic hydroxides not only provides more active sites but also greatly improves the migration of holes from bismuth vanadate to LDH. This facilitates the fast separation and transport of holes, thus retarded the recombination of photogenerated charges. In addition, the synergistic effect of transition metals in LDH plays an important role in the enhancement of PEC water oxidation of the hybrid photoanodes. New water oxidation catalyst introduced in this work hold a great promise to be extended to other photoanodes for advanced performance in the fields of energy conversion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Efficient glycerol electrooxidation reaction (GEOR) over gold@nickel sulfide (Au@NiSx) yolk@shell nanostructures is demonstrated, achieving ≈50.4% glycerol conversion at 10 h, 92.6% selectivity ...toward three‐carbon products, and 90.7% total Faradaic efficiency. By regulating the electrode potential, tartronic acid (TART), one of the highest value‐added intermediates, can be produced with a selectivity as high as 43.1% and a yield of 45.6 µmol cm−2 h−1. A combination of ex situ microstructural analysis, operando Raman, and operando X‐ray absorption measurements reveals a dynamic surface reconstruction course from Au@NiSx to Au@NiSx/NiOOH during the glycerol oxidation process. The unique reconstructed architectures featuring conductive interior NiSx components and active surface high‐valence Ni3+ species account for the superior GEOR performance. Further integration of GEOR with hydrogen evolution reaction is realized by employing Au@NiSx as both anode and cathode electrocatalysts in a two‐electrode configuration. Concomitantly production of TART and hydrogen fuel is accomplished. This study demonstrates that Au@NiSx not only can convert glycerol to TART with remarkable efficiency and selectivity, but also can produce hydrogen at a moderate level. The findings from this study can facilitate the development of dual‐functional electrocatalysts capable of producing high‐value products at both the cathode and anode sides.
Practical use of gold@nickel sulfide (Au@NiSx) yolk@shell nanostructures for efficient glycerol electrooxidation (GEOR) is demonstrated. The unique re‐constructed architectures featuring conductive interior NiSx component and active surface high‐valence Ni3+ species accounted for the superior GEOR performance. Further integration of GEOR with hydrogen evolution reaction is realized by employing Au@NiSx as both anode and cathode electrocatalysts in a two‐electrode configuration.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Bone marrow mesenchymal stem/stromal cells (BMSCs), which are known as multipotent cells, are widely used in the treatment of various diseases via their self-renewable, differentiation, and ...immunomodulatory properties. In-vitro and in-vivo studies have supported the understanding mechanisms, safety, and efficacy of BMSCs therapy in clinical applications. The number of clinical trials in phase I/II is accelerating; however, they are limited in the size of subjects, regulations, and standards for the preparation and transportation and administration of BMSCs, leading to inconsistency in the input and outcome of the therapy. Based on the International Society for Cellular Therapy guidelines, the characterization, isolation, cultivation, differentiation, and applications can be optimized and standardized, which are compliant with good manufacturing practice requirements to produce clinical-grade preparation of BMSCs. This review highlights and updates on the progress of production, as well as provides further challenges in the studies of BMSCs, for the approval of BMSCs widely in clinical application.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Replacement of oxygen evolution reaction (OER) by the more readily oxidized biomass derivatives is considered to be a promising strategy for photoelectrocatalytic water splitting hydrogen production. ...In this work, a biodiesel industrial waste by-product, glycerol, played the critical role for the efficient hydrogen production as well as the highly valuable dihydroxyacetone (DHA) and industrial useful formic acid production. As the glycerol was introduced, a remarkable cathodic shift of the onset potential was observed (∼300 mV) while the current density was 4 times higher compared to the water oxidation. The incident photon-to-current efficiency (IPCE) of BiVO4 photoanode for glycerol oxidation reached about 55%, which was 3 times higher than the system without glycerol. More importantly, during the photoelectrochemical water splitting in glycerol aqueous solution, in addition to the evolved hydrogen gas, glycerol was oxidized to valuable products with 15% dihydroxyacetone (DHA) and 85% formic acid. This strategy not only boosts the hydrogen production efficiency, keeps the photoanode very stable but also makes the biodiesel production more profitable and sustainable.
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•Industrial by-product is used is an effective and economical sacrificial agent for photoelectrochemical hydrogen production.•Significantly improved the photocurrent density and near-complete suppression in surface recombination are achieved.•Glycerol is found to play multi-function in photoelectrochemical cell.•Clean hydrogen and valuable chemicals are produced simultaneously.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study report for the first time an earth-abundant manganese oxide (MnO2) was used for electrocatalytic glycerol oxidation with a satisfactory yield and high selectivity under mild pH media.
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•First report of MnO2 catalyst for electrooxidation of glycerol.•High selectivity toward DHA (∼46%) under high current density (∼6 mAcm−2) could be achieved.•Reaction pathway of glycerol electrooxidation was proposed based on HPLC, Raman spectroscopy, and electrochemical studies.•High DHA selectivity at high potential due to partial transformation of α-MnO2 to δ-MnO2.
In this study, earth-abundant manganese oxide (MnO2) was used as a catalyst for the electrocatalytic glycerol oxidation with a satisfactory yield and high selectivity under mild pH media; that is, the high current density of 6.0 mA cm−2 and selectivity of ca. 46% for dihydroxyacetone (DHA). MnO2 also exhibited reasonable durability without considerable changes for 3 h. More importantly, by combination of operando Raman and electrochemical studies, a tentative reaction pathway was also proposed. It is found that high selectivity of formic acid at low potential was due to predominant coverage of α-MnO2 on catalyst surface. Meanwhile, at high applied potential, partial transformation of α-MnO2 to δ-MnO2 causes decreasing C-C bond cleavage, leading to high DHA selectivity. The results of this work not only demonstrate that MnO2 holds promise as an efficient electrocatalyst for selectively producing DHA but also provides realistic details on electrochemically generated species under working condition.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Microscopic features (e.g., pore shapes, sizes, and distribution) in porous material substantially affect the overall mechanical properties such as stiffness and strength. In turn, these material ...properties determine the macroscopic behaviors of fracture in the porous material. In certain cases, macroscopic properties can be derived from the porous skeleton and void ratio (i.e., porosity), but in many other cases, such derivation is a challenging task. This paper presents a numerical investigation of microporosity and micropore shapes effect on the macrofracture behavior in porous amorphous silica. For this study, we extend the recently proposed combined molecular dynamic (MD) and phase-field (PF) fracture modeling approach by including different pore shapes in the atomistic domain. In the MD simulations, we adopt ReaxFF to evaluate the material properties, where four different micropore cases are considered. Based on the material properties derived from MD simulations, the macrofracture propagation of porous media is studied using hybrid PF simulation. In the characterization of the pore structure, the concept of pore ligament is proposed to relate the pore shape and the critical energy release rate. Two classical fracture problems were used to evaluate the effect of micropore shape on the macrofracture behavior. The results of the case studies show that although the micropore shapes change the macrofracture behaviors, these effects vary with the geometry and loading conditions of macroscopic boundary value problems. The case study also shows that the influence of micropore structure can be captured at the macroscopic level through the material properties derived from the MD simulations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A solution‐processed nanoarchitecture based on PbS quantum dots (QDs) and multi‐walled carbon nanotubes (MWCNTs) is synthesized by simply mixing the pre‐synthesized high‐quality PbS QDs and ...oleylamine (OLA) pre‐functionalized MWCNTs. Pre‐functionalization of MWCNTs with OLA is crucial for the attachment of PbS QDs and the coverage of QDs on the surface of MWCNTs can be tuned by varying the ratio of PbS QDs to MWCNTs. The apparent photoluminescence (steady‐state emission and fluorescence lifetime) “quenching” effect indicates efficient charge transfer from photo‐excited PbS QDs to MWCNTs. The as‐synthesized PbS‐QD/MWCNT nanoarchitecture is further incorporated into a hole‐conducting polymer poly(3‐hexylthiophene)‐(P3HT), forming the P3HT:PbS‐QD/MWCNT nanohybrid, in which the PbS QDs act as a light harvester for absorbing irradiation over a wide wavelength range of the solar spectrum up to near infrared (NIR, ≈1430 nm) range; whereas, the one‐dimensional MWCNTs and P3HT are used to collect and transport photoexcited electrons and holes to the cathode and anode, respectively. Even without performing the often required “ligand exchange” to remove the long‐chained OLA ligands, the built nanohybrid photovoltaic (PV) device exhibits a largely enhanced power conversion efficiency (PCE) of 3.03% as compared to 2.57% for the standard bulk hetero‐junction PV cell made with P3HT and 6,6‐Phenyl‐C61‐Butyric Acid Methyl Ester (PCBM) mixtures. The improved performance of P3HT:PbS‐QD/MWCNT nanohybrid PV device is attributed to the significantly extended absorption up to NIR by PbS QDs as well as the effectively enhanced charge separation and transportation due to the integrated MWCNTs and P3HT. Our research results suggest that properly integrating QDs, MWCNTs, and polymers into nanohybrid structures is a promising approach for the development of highly efficient PV devices.
A novel poly(3‐hexylthiophene):PbS‐quantum‐ dot/multi‐walled carbon nanotube (P3HT:PbS‐QD/MWCNT) nanohybrid photovoltaic device with significantly enhanced near‐infrared (NIR) photon‐to‐current conversion is developed by employing PbS QDs as light harvester for absorbing a wide wavelength range irradiation up to NIR, while the one‐dimensional MWCNTs and the conducting polymer P3HT are used to collect and transport the photoelectrons and photoholes, respectively.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In this work, we present an easy and scalable electrodeposition protocol that operates in a deep eutectic solvent, used to prepare self-supported Ni-Fe alloy films directly grown on copper foils. ...Unlike electrodeposition in aqueous baths, alloy compositions deposited in deep eutectic solvent are found to be the same as in plating solution owing to the enlargement of the deposition window and secondary reaction suppression. By rationally tuning the Ni/Fe ratio in deep eutectic solvent plating solution, the best oxygen evolution reaction performance was achieved by a Ni
75
Fe
25
catalyst, which requires only a 316 mV overpotential to reach a current density of 10 mA cm
−2
, while its Tafel slope is as low as 62 mV dec
−1
. This catalyst can operate at 10 mA cm
−2
with negligible activity degradation for over 10 h, promising its potential use as a low-cost, high-performance and stable electrocatalyst in water splitting devices.
In this work, we present an easy and scalable electrodeposition protocol that operates in a deep eutectic solvent, used to prepare self-supported Ni-Fe alloy films directly grown on copper foils.
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