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Baihua Cui

Bio: Baihua Cui is an academic researcher from Tianjin University. The author has contributed to research in topics: Overpotential & Oxygen evolution. The author has an hindex of 7, co-authored 10 publications receiving 174 citations. Previous affiliations of Baihua Cui include Agency for Science, Technology and Research & Dongguan University of Technology.

Papers
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Journal ArticleDOI
TL;DR: In this article, a hybrid OER catalyst was prepared by the growth of CoFe-LDH (layered double hydroxide) on the surface of Ti3C2 MXene nanosheets, which exhibits superior OER performance than the state-of-the-art RuO2.

136 citations

Journal ArticleDOI
TL;DR: Dislocation-strained IrNi nanoparticles loaded on a carbon nanotube sponge driven by unsteady thermal shock in an extreme environment are reported here as a highly efficient hydrogen evolution reaction (HER) catalyst.
Abstract: Designing high-performance and low-cost electrocatalysts is crucial for the electrochemical production of hydrogen. Dislocation-strained IrNi nanoparticles loaded on a carbon nanotube sponge (DSIrNi@CNTS) driven by unsteady thermal shock in an extreme environment are reported here as a highly efficient hydrogen evolution reaction (HER) catalyst. Experimental results demonstrate that numerous dislocations are kinetically trapped in self-assembled IrNi nanoparticles due to the ultrafast quenching and different atomic radii, which can induce strain effects into the IrNi nanoparticles. Such strain-induced high-energy surface structures arising from bulk defects (dislocations), are more likely to be resistant to surface restructuring during catalysis. The catalyst exhibits outstanding HER activity with only 17 mV overpotential to achieve 10 mA cm-2 in an alkaline electrolyte with fabulous stability, exceeding state-of-the-art Pt/C catalysts. These density functional theory results demonstrate that the electronic structure of as-synthesized IrNi nanostructure can be optimized by the strain effects induced by the dislocations, and the free energy of HER can be tuned toward the optimal region.

112 citations

Journal ArticleDOI
TL;DR: In this paper, a Fe-Ni(OH)2/Ni3S2 nanoarray was used as a free-standing anodic electrode in alkaline artificial seawater.
Abstract: Development of efficient non-precious catalysts for seawater electrolysis is of great significance but challenging due to the sluggish kinetics of oxygen evolution reaction (OER) and the impairment of chlorine electrochemistry at anode. Herein, we report a heterostructure of Ni3S2 nanoarray with secondary Fe-Ni(OH)2 lamellar edges that exposes abundant active sites towards seawater oxidation. The resultant Fe-Ni(OH)2/Ni3S2 nanoarray works directly as a free-standing anodic electrode in alkaline artificial seawater. It only requires an overpotential of 269 mV to afford a current density of 10 mA·cm−2 and the Tafel slope is as low as 46 mV·dec−1. The 27-hour chronopotentiometry operated at high current density of 100 mA·cm−2 shows negligible deterioration, suggesting good stability of the Fe·Ni(OH)2/Ni3S2@NF electrode. Faraday efficiency for oxygen evolution is up to ∼ 95%, revealing decent selectivity of the catalyst in saline water. Such desirable catalytic performance could be benefitted from the introduction of Fe activator and the heterostructure that offers massive active and selective sites. The density functional theory (DFT) calculations indicate that the OER has lower theoretical overpotential than Cl2 evolution reaction in Fe sites, which is contrary to that of Ni sites. The experimental and theoretical study provides a strong support for the rational design of high-performance Fe-based electrodes for industrial seawater electrolysis.

110 citations

Journal ArticleDOI
TL;DR: In this article, a non-equilibrium high-temperature (>1400 K) thermal-shock method is reported to induce rich dislocations in Pt nanocrystals (Dr-Pt).
Abstract: Crystal structure engineering of nanomaterials is crucial for the design of electrocatalysts. Inducing dislocations is an efficient approach to generate strain effects in nanomaterials to optimize the crystal and electronic structures and improve the catalytic properties. However, it is almost impossible to produce and retain dislocations in commercial mainstream catalysts, such as single metal platinum (Pt) catalysts. In this work, a non-equilibrium high-temperature (>1400 K) thermal-shock method is reported to induce rich dislocations in Pt nanocrystals (Dr-Pt). The method is performed in an extreme environment (≈77 K) created by liquid nitrogen. The dislocations induced within milliseconds by thermal and structural stress during the crystallization process are kinetically frozen at an ultrafast cooling rate. The high-energy surface structures with dislocation-induced strain effects can prevent surface restructuring during catalysis. The findings indicate that a novel extreme environmental high-temperature thermal-shock method can successfully introduce rich dislocations in Pt nanoparticles and significantly boost its hydrogen evolution reaction performance.

39 citations

Journal ArticleDOI
TL;DR: In this article, a regulated synthesis of eutectic structured Ni3S2/NiS nanorods was reported, which demonstrated a fantastic electrochemical performance as a freestanding electrode for hybrid SCs.

31 citations


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Journal ArticleDOI
12 Aug 2020-ACS Nano
TL;DR: By clarifying the roles of individual material components in the MXene hybrids, this review provides design strategies to synergistically couple MXenes with associated materials for highly efficient and durable catalytic applications.
Abstract: Electro-, photo-, and photoelectrocatalysis play a critical role toward the realization of a sustainable energy economy. They facilitate numerous redox reactions in energy storage and conversion systems, enabling the production of chemical feedstock and clean fuels from abundant resources like water, carbon dioxide, and nitrogen. One major obstacle for their large-scale implementation is the scarcity of cost-effective, durable, and efficient catalysts. A family of two-dimensional transition metal carbides, nitrides, and carbonitrides (MXenes) has recently emerged as promising earth-abundant candidates for large-area catalytic energy storage and conversion due to their unique properties of hydrophilicity, high metallic conductivity, and ease of production by solution processing. To take full advantage of these desirable properties, MXenes have been combined with other materials to form MXene hybrids with significantly enhanced catalytic performances beyond the sum of their individual components. MXene hybridization tunes the electronic structure toward optimal binding of redox active species to improve intrinsic activity while increasing the density and accessibility of active sites. This review outlines recent strategies in the design of MXene hybrids for industrially relevant electrocatalytic, photocatalytic, and photoelectrocatalytic applications such as water splitting, metal-air/sulfur batteries, carbon dioxide reduction, and nitrogen reduction. By clarifying the roles of individual material components in the MXene hybrids, we provide design strategies to synergistically couple MXenes with associated materials for highly efficient and durable catalytic applications. We conclude by highlighting key gaps in the current understanding of MXene hybrids to guide future MXene hybrid designs in catalytic energy storage and conversion applications.

278 citations

Journal Article
18 Jun 2020-Elements
TL;DR: In this paper, a metal-organic framework containing Zn, N, and B was used as the precursor to synthesize dual-doped and metal-free porous carbon materials as efficient ORR/OER bifunctional electrocatalysts.
Abstract: Rechargeable Zn-air batteries are under intensive studies because of their high-energy density, low cost, and safety. However, their wide application is prevented by several remaining technical issues, one of which is the lack of suitable bifunctional cathodic catalysts for oxygen reduction reaction (ORR) during discharging and oxygen evolution reaction (OER) during charging. Due to low material cost and wide distribution, carbon-based materials may serve as promising electrocatalysts, while doping heteroatoms such as nitrogen or boron can effectively enhance their catalytic activity. Herein, we pyrolyze a metal-organic framework containing Zn, N, and B as the precursor to synthesize dual-doped and metal-free porous carbon materials as efficient ORR/OER bifunctional electrocatalysts. The surface area of obtained carbon materials can be greatly enhanced by pyrolysis under H 2 -containing atmosphere. In addition, N and B are evenly distributed within the carbon materials due to the crystalline MOF precursor. The resultant carbon materials exhibit high ORR and OER catalytic activities in both half-cell and single-cell battery measurements. Our study has demonstrated for the first time that MOFs can be used as precursors to synthesize metal-free ORR/OER bifunctional cathodic electrocatalysts with great potential in rechargeable Zn-air batteries.

239 citations

06 Nov 2019
TL;DR: In this paper, state-of-the-art PtNi/C nanocatalysts with distinct atomic composition, size, shape and density of disorder were synthesized.
Abstract: The oxygen reduction reaction (ORR) is a key reaction for energy conversion and storage systems such as polymer electrolyte membrane fuel cells (PEMFCs). Studies on Pt and Pt-transition metal alloy single crystals have established that the ORR is best electrocatalyzed on bimetallic alloys and at (111) facets. Combining alloying and ensemble effects recently led to 20-30-fold enhancement of the specific activity (normalized per real cm 2 of catalyst) for the ORR on PtNi/C nanooctahedra relative to Pt/C nanoparticles. However, due to the highly oxidizing conditions of the PEMFC cathode, the stability of PtNi/C octahedra is poor in PEMFC cathode operating conditions, thus compromising their utilization in real devices. Strikingly, it also turned out recently that structurally-disordered PtNi nano-catalysts, such as hollow PtNi/C nanoparticles, dealloyed PtNi/C nanoparticles, PtNi aerogels or PtNi nanowires feature highly desirable and sustainable ORR activity (x 10-12 in specific activity relative to pure Pt/C). However, to date, the mechanisms of this unexpected ORR activity enhancement remain unclear, and prevent further development of this vital technology for a carbon-free energy future. To shed fundamental light onto these issues, state-of-the art PtNi/C nanocatalysts with distinct atomic composition, size, shape and density of disorder were synthesized. Their disorder was quantified experimentally, using the values of microstrain (a parameter accessible by the Rietveld refinement of wide-angle X-ray scattering patterns) that is representative of the local distortion of a crystal lattice. Thanks to ab initio calculations, the contributions of bulk and surface structural disorder were disentangled, and a new parameter, the surface distortion (SD), was established. The SD descriptor was used to rationalize the ORR activity enhancement of the two classes of materials (structurally-ordered and structurally-disordered), and to probe their stability in simulated PEMFC cathode operating conditions.

226 citations

Journal ArticleDOI
TL;DR: In this article, termination modification and heteroatom incorporation are applied to optimize the chemical and electronic configurations of active sites for intrinsically enhanced catalytic kinetics while various nanostructures and hybridizations are fabricated to increase the density and accessibility of the active sites.
Abstract: Most recently, two-dimensional (2D) transition-metal carbides (MXenes) have been demonstrated to be promising electrocatalysts owing to their unique chemical and electronic properties, e.g., metallic conductivity, high hydrophilicity, and tunable surface terminations. Herein, representative progress achieved in MXenes as hydrogen evolution reaction electrocatalysts is reviewed both experimentally and theoretically. Briefly, termination modification and heteroatom incorporation are applied to optimize the chemical and electronic configurations of active sites for intrinsically enhanced catalytic kinetics while various nanostructures and hybridizations are fabricated to increase the density and accessibility of active sites. Then, the achievements of MXene-based catalysts in other electrocatalysis processes are also summarized, including the oxygen evolution/reduction reaction, carbon dioxide reduction reaction and nitrogen reduction reaction. Finally, current challenges and future research directions for MXene-based electrocatalysis are discussed.

164 citations