Xinwei Cui

Zhengzhou University | zzu · College of Materials Science and Engineering

2D heterostructures offer a great opportunity in seeking high-performing energy storage materials; however, performance ceiling exists, limited by their van-der-Waals (vdW) interactions. Here, we explore a novel 2D, amorphous MoO3-x (aMoO3-x) on Ti3C2-MXene, non-vdW heterostructure via a facile synthesis route. Density functional theory computation...

The design of pseudocapacitive electrodes that exhibit high‐rate and high volumetric capacitances is a big challenge, since it requires subtle modulation of ion‐intercalation structures that are able to achieve high electrochemical activity, fast ion transport, and facilitated electron transfer, simultaneously. Herein, controllable and selective et...

The pressing crisis of clean water shortage requires membranes to possess effective ion sieving as well as fast water flux. However, effective ion sieving demands reduction of pore size, which inevitably hinders water flux in hydrophilic membranes, posing a major challenge for efficient water/ion separation. Herein, we introduce anomalous water mol...

Ni-rich layered cathodes are promising for achieving high energy density, yet suffer from dramatic rate and capacity decay on cycling, which originates from chemo-mechanical failures with fast growth of an electrical and ionic insulating rock-salt phase on the surface. Apart from general approaches of applying inert coating layers, here we regulate...

A large amount of lithium-ion storage in Si-based anodes promises high energy density yet also results in large volume expansion, causing impaired cyclability and conductivity. Instead of restricting pulverization of Si-based particles, herein, we disclose that single-walled carbon nanotubes (SWNTs) can take advantage of volume expansion and induce...

MXene is a promising electrode material for both high volumetric capacitance and high-rate performance in supercapacitors. However, the current study has mainly focused on the monometallic element Ti3C2Tx MXene until now, while the bimetallic and multimetallic MXene have received comparatively less attention. In this work, we demonstrate that the e...

Captured by relatively low energy consumption and harmful gas‐emission, direct regeneration has captured numerous attention, but still suffers from different particle sizes and diverse doping hetero‐elements, hardly meeting the market demand. Herein, assisted by the crush‐sinter regeneration from element to grain further to particle, homogenized re...

Sodium-selenium (Na-Se) batteries have gained attention due to their high energy density and power density, resulting from the liquid–liquid reaction at the interface in the dimethoxyethane electrolyte. Nevertheless, the pronounced shuttle effect of polyselenides causes low coulomb efficiency and inadequate cycling stability for Na-Se batteries. He...

High-theoretical-capacity antimony (Sb) anodes hold promise for high-performing sodium-ion storage, yet suffer from huge volume change. In solving this obstacle, traditional strategies normally incorporate nanosized Sb with low-density conductive materials, which, in turn, sacrifice volumetric performance. Here, we report micro-sized Sb particles (...

Electron injection effectively induces the formation of a 1T-rich phase to address the low conductivity of MoSe2. Nevertheless, overcoming the inherent metastability of the 1T phase (particularly during the conversion reactions that entail the decomposition–reconstruction of MoSe2 and volume expansion) remains a challenge. Guided by DFT results, we...

Effective ion sieving demands reduction of pore size, which inevitably hinders water flux in hydrophilic membranes, posing a major challenge for precise and ultrafast molecular sieving. Herein, we introduce anomalous liquid gating from nanofiltration membranes full of graphene capillaries at 6 Å with a contact angle of 84°, fabricated from spontane...

Lithium–sulfur (Li‐S) batteries have emerged as one of the most attractive alternatives for post‐lithium‐ion battery energy storage systems, owing to their ultrahigh theoretical energy density. However, the large‐scale application of Li–S batteries remains enormously problematic because of the poor cycling life and safety problems, induced by the l...

Rational design of highly efficient ethanol electrooxidation catalysts requires modulation of their band structure, yet most of the understanding stops at either upshift or downshift of d-band center that facilitates only a portion of ethanol oxidation reaction (EOR) process. Herein, we take in-situ formed carbonaceous intermediates as an essential...

Two-dimensional (2D) transition metals carbides, nitrides, or carbonitrides, regarded as MXenes, holds great promise into an extensive scope of applications such as efficient catalysis and energy conversion and storage materials....

Since the discovery of 2D materials, 2D material nanofiltration (NF) membranes have attracted great attention and are being developed with a tremendously fast pace, due to their energy efficiency and cost effectiveness for water purification. The most attractive aspect for 2D material NF membranes is that, anomalous water and ion permeation phenome...

The design and synthesis of 2D heterostructured materials for water splitting are normally based on van der Waals (vdW) nanosheets, but this approach is gradually approaching a performance ceiling in terms of activity and stability. Herein, a novel heterostructured system is explored based on 2D non‐vdW and conductive nanosheets. Notably, the inter...

Here, we demonstrate, for the first time, that Co-MoO3-x nanocrystals (NCs) have been synthesized with the assistance of supercritical CO2. Their unique structural features of transition-metal doping and high oxygen...

A heterostructure of crystallized MoO2/amorphous MoO3-x was constructed via reduction of crystalline MoO3 by Mo metal via a hydrothermal method. The heterostructure possesses an excellent photothermal conversion performance (61.5%). Abstract The heterostructure of crystallized MoO2/amorphous MoO3-x was firstly constructed via reduction of crystall...

Li-substituted, manganese-based, layered oxides Na x Li0.18Mn0.66Co0.17Ni0.17O2+δ (x = 0.54, 0.66, 0.78, and 0.90) have been investigated as one kind of high-performance cathode materials for sodium ion batteries (SIBs). Phase compositions and local structures of the cathode materials with varying sodium content were elucidated by powder X-ray diff...

Energy-efficient membranes are urgently needed for water desalination and separation due to ever-increasing demand for fresh water. However, it is extremely challenging to increase membrane water flux and simultaneously achieve high rejection rates of cations or organic dyes. Herein, we report a tannic acid (TA) assisted exfoliation method to fabri...

Lithium metal batteries (LMBs) show tremendous potential in energy storage due to ultrahigh energy densities. Nevertheless, maintaining a stable solid electrolyte interphase (SEI) and suppressing the growth of dendrite are hard to achieve with conventional liquid electrolytes. Gel/solid polymer electrolytes are considered sought-after candidates to...

Supercapacitors can deliver high electrical power because of fast ion adsorption/desorption on the surface or surface redox reactions, which, in turn, restrict their energy density. To break surface-storage ceiling and further improve the energy density, here, we develop a cost-effective, layered material made of amorphous metal-organic nanosheets,...

Many challenging issues are encountered along the petroleum production such as the wettability alteration of reservoir solids due to deposition of petroleum materials, stabilization/destabilization of water-in-oil and oil-in-water emulsions and treatment of tailings water. All these problems are essentially driven by the fundamental intermolecular...

A facile and scalable polyzwitterion-polydopamine coating strategy has been developed to functionalize substrates and sponges. This approach, for the first time, achieves superior regenerable underwater self-cleaning of stubborn asphaltenes-containing heavy...

In this paper, Cr3C2/epoxy composite material was prepared by infiltration of the epoxy to porous Cr3C2 ceramic. The microstructures, hardness and wear resistance of the composite materials were investigated with the porous Cr3C2 as a compared material by scanning electron microscope, hardness tester and pin-on-disc tribometer. Most pores in the po...

High surface area porous carbons (up to 3768 m2 g-1) were prepared from as-synthesized polyaniline (PANI) by KOH activation. The structural characteristics of the resulting carbons have been comprehensively studied in terms of activation parameters such as activation temperature, KOH ratio and preheating temperature. It has been found that increasi...

A unique structure of graphene-wrapped mesoporous single crystals (MSCs) is successfully applied on low-cost MnCO3 for lithium-ion batteries (LIBs). In a departure from previous high-temperature (>500°C) synthesis approaches for MSCs, we develop a simple, low-temperature (70°C) and template-free method, referrers to as dynamic floating electrodepos...

Highly porous carbons were prepared by using polyaniline (PANI) as a carbon precursor and KOH as an activating agent via a one-step chemical activation process. The effects of the activation parameters such as activation temperature, KOH-PANI weight ratio and pre-heating temperature were fully investigated, through which the pore structure and the...

High performance rechargeable batteries are urgently demanded for future energy storage systems. Here, we adopted a lithium-carbon battery configuration. Instead of using carbon materials as the surface provider for lithium-ion adsorption and desorption, we realized induced fluorination of carbon nanotube array (CNTA) paper cathodes, with the sourc...

A simple methodology is developed to directly synthesize three-dimensional (3D) electrochemically supercapacitive arrays, consisting of multiwalled carbon nanotubes conformally covered by nanocrystalline vanadium nitride, firmly anchored to glassy carbon or Inconel electrodes. These nanostructures demonstrate a respectable specific capacitance of 2...

Ce or CeO2 is often added to Fe–Cr–Ni base alloys to enhance protective Cr2O3 ceramic scale formation. In high‐temperature carbonaceous reducing environments, however, it is still unsolved that Ce‐containing alloys often exhibited increased carburization and coke formation. This research is aimed at understanding the mechanism of Ce‐enhanced coke f...

Porous chromium carbide structures have been synthesized through reactive sintering of chromium oxides in carbonaceous reducing environments. The process is simple and can be used to fabricate large size porous structures. It has been characterized that the pores in the porous structure are open in nature and the size of pores in the same porous st...

Electrochemical supercapacitors (ECs), characteristic of high power and reasonably high energy densities, have become a versatile solution to various emerging energy applications. This critical review describes some materials science aspects on manganese oxide-based materials for these applications, primarily including the strategic design and fabr...

An in-depth study of morphology-controlled growth of manganese oxide nanostructures from acetate-containing aqueous solutions was carried out. By varying the deposition parameters, including solution composition, pH value, deposition temperature and current density, a series of manganese oxide nanostructures, including continuous coatings with equi...

Chromium carbide (Cr3C2) and carbon nanotubes (CNTs) improved Ti/SnO2–Sb2O4 electrodes were successfully fabricated using pulse electro-co-deposition technique. The morphologies and phase constituents of these electrodes were characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD). The service lifetime of anode was signif...

The unique properties of carbon nanotubes (CNTs) strongly depend on their structures. In this study, the growth kinetics of ultra-long multi-walled CNT (MWCNT) arrays by water-assisted chemical vapor deposition (WACVD) has been investigated based on the statistical studies of CNT wall number. It was found that the kinetics of MWCNT arrays in WACVD...

Mn3O4 nanoparticles have been homogenously deposited within highly dense, millimeter-long carbon nanotube array (CNTA) by dip-casting method from non-aqueous solutions. After modified with Mn3O4 nanoparticles, CNTAs have been changed from hydrophobic to hydrophilic without their alignment and integrity being destroyed. The hydrophilic Mn3O4/CNTA co...

A three-dimensional ultralong-CNTA-supported Pd-based anode (Pd/CNTA) has been designed for ethanol oxidation. Nano-size Pd particles were uniformly attached to the surface of CNTs within CNTA by using pulse electrodeposition technique. The as-prepared Pd/CNTA anode is featured with low ion diffusion resistance, vertical electron conduction, and la...

Multi-walled carbon nanotube (MWCNT) array growth demonstrates lengthening and thickening stages by chemical vapor deposition (CVD) in the presence (water-assisted CVD (WACVD)) and absence (conventional CVD (CCVD)) of water. In the lengthening stage of WACVD, CNT wall number remains constant and catalysts preserve the activity; while in the thicken...

Carbon nanotube (CNT) doped SnO2-Sb2O4 coating was successfully electro-codeposited on a Ti substrate using the pulse electro-codeposition technique. The physicochemical and electrochemical properties as well as the electrocatalytic activity of Ti/SnO2-Sb2O4-CNT electrodes were investigated. The service time of the Ti/SnO2-Sb2O4-CNT electrode is 8....

MnCr2O4 and Cr2O3 are two important protective oxides on the surface of austenitic alloys used for ethylene cracking. This investigation is focused on the effect of CeO2 on the stability of MnCr2O4 and Cr2O3 in high temperature carbonaceous environments. The presence of 5% CeO2 in MnCr2O4 increased the carburization rate of the MnCr2O4 spinel throu...

This research is aimed at synthesizing millimeter-scale carbon nanotube arrays (CNTA) by conventional chemical vapor deposition (CCVD) and water-assisted chemical vapor deposition (WACVD) methods, and exploring their application as catalyst supports for electrochemical supercapacitors. The growth mechanism and growth kinetics of CNTA under differen...

The carbon nanotube-silver composite (Ag-CNT) is a new class of multifunctional materials with potential applications such as sensors, catalysts, biodisinfection, and sorbents. A simple method combining wet-chemistry and thermal reduction was adopted to synthesize silver on the surface of the CNT. The synthesized Ag-CNT was tested as a sorbent for...

Vertically aligned millimeter-scale carbon nanotube (CNT) arrays have been successfully deposited on both Fe(3nm)/Al2O3 and Fe(1nm)/Al2O3 catalyst films under different optimum pretreatment conditions by catalytic chemical vapor deposition. By investigating the catalyst particles before CNT array growth, it has been found that inter-particle spacin...

Electrochimica Acta j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / e l e c t a c t a a b s t r a c t The electrochemical cycling behavior of nanocrystalline MnO 2 coatings with a defective antifluorite struc-ture, prepared by anodic electrodeposition, was investigated in terms of morphological and structural evoluti...

The electrochemical cyclability mechanism of nanocrystalline MnO2 electrodes with rock salt-type and hexagonal ɛ-type structures was investigated to determine the relationship between physicochemical feature evolution and the corresponding electrochemical behaviour of MnO2 electrodes. Rock salt MnO2 and hexagonal ɛ-MnO2 electrodes, with fibrous and...

Nanocrystalline Ni/Cu alloy matrix–Al metal particle composite coatings have been successfully developed via sediment codeposition (SCD) method. As high as 29 vol.% Al particles could be incorporated in the nanocrystalline Ni/Cu alloy matrix which has an average grain size of 16 nm. Adding conductive Al particles in the electrolyte shifted polariza...

The crystal structure of anodically electrodeposited MnO2 nanocrystals can be manipulated by introducing complexing agents in the electrodeposition solutions. MnO2 nanocrystals with three types of crystal structures were observed: hexagonal ε-MnO2 (complex-free), defective rock salt MnO2 (ethylenediaminetetraacetic acid), and defective antifluorite...

Poor surface finish and coarse dendrite structure are the major challenges in direct-current (dc) plating of nanosized Ni-Cu alloy coatings. This investigation was initiated to understand the effect of saccharin on the formation of nanosized Ni-Cu alloy coatings by sediment codeposition, and the role of saccharin in improving surface finish and sup...