Zhigang Xiong

The University of Queensland | UQ · School of Chemical Engineering

Layered double hydroxides (LDHs) are versatile stable materials, whose structures are two-dimensional cationic layers stacking together with various anions via electrostatic interactions. LDHs have been widely used in synthesis, pharmaceuticals, and catalysis. Recently, LDHs, LDH-based photocatalysts, and LDH derivatives (such as mixed metal oxides...

Composite materials consisting of layered titanate and cadmium sulfide (CdS) particles were prepared via consecutive ion exchange and precipitation processes. Samples with different CdS loadings were characterized using X-ray diffraction, physical adsorption/desorption of nitrogen, scanning/transmission electron microscopy and ultraviolet-visible d...

Metal@TiO2 composites with a core–shell structure possess multifunctional properties. The demonstrated protocols for synthesizing such materials involve multiple steps, requiring precise control over the particle uniformity of the core and shell thickness, as well as complex surface modification. A simple approach to synthesizing metal@TiO2 hybrid...

A new approach to preparing porous carbons with desirable pore structure and morphology is demonstrated by using an appropriate pair of polycarboxylic acid/anhydride and diamine in the presence of a metal salt without a sacrificial template.

Dual-phase TiO2 photocatalysts with controllable ratio of anatase to rutile were synthesized, and evaluated using the degradation of Rhodamine B (RhB) under UV light irradiation. The TiO2 samples prepared by one-pot redox reactions in the presence of graphene oxide (GO) were characterized by X-ray diffraction, physical adsorption-desorption of nitr...

A facile two-step method is developed to fabricate three-dimensional ordered macroporous (3DOM) gold-loaded titania (TiO2) photonic crystals with enhanced photocatalytic activities. Firstly, a mixed solution of polystyrene (PS) colloids, chloroauric acid and titanium(IV)-bis-lactato-bisammonium dihydroxide (TiBALDH) sol was co-assembled into PS/TiO...

The hard template approach for preparing porous materials allows one to be able to control pore size and particle morphology. However, the cost of this method is a crucial factor for mass production. In this work, commercially available low-cost hydrophobic CaCO3 spheres (HCS) of different particle sizes were used as hard templates for preparing po...

In this work, mesoporous carbon-coated LiFePO4 nanocrystals further co-modified with graphene and Mg(2+) doping (G/LFMP) were synthesized by a modified rheological phase method to improve the speed of lithium storage as well as cycling stability. The mesoporous structure of LiFePO4 nanocrystals was designed and realized by introducing the bead mill...

Composite titanate@TiO2 nanobelts with a core-shell heterostructure were prepared and applied for the photocatalytic degradation of benzoic acid (BA) under UV light irradiation. The composite materials prepared using layered titanate with or without the presence of cetyl trimethylammonium bromide (CTAB) were characterized by X-ray diffraction, phys...

The ever-increasing demands for energy and environmental concerns due to burning fossil fuels are the key drivers of today's R&D of innovative energy storage systems. This paper provides an overview of recent research progress in graphene-based materials as electrodes for electrochemical energy storage. Beginning with a brief description of the imp...

A novel 3D nanostructure consisting of Ni(OH)2 nanoparticles, carbon nanotubes (CNTs), and reduced graphene oxide with an extremely high electrocapacitance is described. The nanostructure consists of CNTs with embedded Ni(OH)2 nanoparticles as pillars for reduced graphene oxide sheets. Electrochemical results show that the composite displays specif...

This paper reports a facile method for the preparation of graphene-based composite materials consisting of reduced graphene oxide (RGO) and CdS nanoparticles. Both CdS and the RGO-CdS composite were prepared in aqueous medium and without the use of obnoxious organic solvent. The synthetic method was based on the reduction of graphene oxide (GO) by...

Molecular iodine has been studied, for the first time, as a sensitizer for the degradation of 2,4,6-trichlorophenol (TCP) in aqueous solution under visible light (λ ≥ 450 nm). TCP was degraded in the presence of commercial I(2), but the reaction rate decreased significantly after 2 h. When a solution of NaI and H(2)O(2) was used as an iodine source...

Anatase TiO(2) with specifically exposed facets has been extensively studied for maximizing its photocatalytic activity. However, most previous preparation methods involve high-pressure processing and corrosive chemicals. Few works have been conducted on hierarchical composite nanostructures assembled from well-defined TiO(2) nanocrystals. Here, we...

Coating of mesoporous TiO2 nanocrystalline films on stainless steel (Grade 304) was conducted using an evaporation-induced self-assembly (EISA) process in the presence of a Pluronic F127 triblock copolymer. The photocatalytic properties of mesoporous TiO2 films were evaluated using orange II in aqueous solution under ultraviolet irradiation. Surfac...

The efficient antibacterial activity of silver-modified mesoporous TiO2 materials with different silver contents were investigated under weak ultraviolet light (UVA) (200 mu W) irradiation using Escherichia coli (E. coil) as a model strain. The comparison with the antibacterial results of three silver-modified TiO2 photocatalysts indicated that sam...

Gold (Au) nanoparticles (NPs) supported on mesoporous silica were prepared using a one-pot synthesis method in the presence of thioether functionality -(CH(2))(3)-S-S-S-S-(CH(2))(3). Bis(triethoxysilyl) propane tetrasulfide was used as the source of thioether functionality. The complexation of thioether groups with tetrachloroauric anion (AuCl(4)(-...

Reduced graphene oxide (RGO) was respectively modified with tin dioxide (SnO2) and titanium dioxide (TiO2) via a direct redox reaction between the graphene oxide (GO) and the reactive cations Sn2+ and Ti3+, forming RGO-SnO2 and RGO-TiO2 composites. During this redox reaction, GO was reduced to RGO while Sn2+ and Ti3+ were oxidized to SnO2 and TiO2,...

Silver-modified graphene oxide nanosheets (Ag-GO) were prepared and used as a novel antibacterial material, which exhibited a superior antibacterial activity towards Escherichia coli (E. coli) due to the synergistic effect of graphene oxide and silver nanoparticles.

A sandwich-vacuum method was demonstrated for the fabrication of titania (TiO(2)) binary inverse opals with an open surface. In this method, a moisture-stable TiO(2) precursor was backfilled into the interstitial spaces of polystyrene binary colloidal crystals (PS bCCs), which served as a template. Removal of the template by calcination yielded TiO...

Previously, it was found that reduced graphene oxide (RGO) can degrade rhodamine B (RhB) under visible-light irradiation, but with an extraordinarily slow rate. It was also found that modification of RGO with gold nanoparticles can dramatically accelerate the photoreaction rate. Herein, we describe the preparation and photocatalytic properties of c...

Mesoporous anatase (TiO(2)) was modified with silver (Ag) nanoparticles using a photoreduction method. Performance of the resulting TiO(2)-Ag nanocomposites for water purification was evaluated using degradation of Rhodamine B (RhB) and disinfection of Escherichia coli (E. coli) under ultraviolet (UV) irradiation. The composites with different Ag l...

Stable mesoporous anatase TiO2 with a large surface area has been prepared by removing the block coploymer template using photocatalysis.

Graphene oxide (GO) and reduced graphene oxide (RGO) platelets were pillared with carbon nanotubes (CNTs) by using the chemical vapor deposition (CVD) method with acetonitrile as the carbon source and nickel nanoparticles as the catalyst, aimed to prepare graphene-based materials with a high surface area and a good electrical conductivity. Characte...

Graphene modified with gold nanoparticles displayed an excellent visible-light photocatalytic performance in degrading dyes in water.

Semiconductor-mediated heterogeneous photocatalysis is a promising technology for water purifications without generating harmful by-products. The photocatalyst with designed physicochemical properties is the key in the process. Utilization of particulate photocatalysts will create some technological problems, such as difficulty in recycling and man...

Organic sulfides are malodorous compounds in environment. In this work, deodorization of model substrates, methyl phenyl sulfide, 2-mercaptobenzoic acid and benzyl 2-propenyl sulfide, have been studied in an aerated methanolic aqueous solution under visible light irradiation (lambda>450nm), using metal phthalocyanine sulfonate (MPcS, M=Al, Pd) as a...

Several studies have shown that addition of NaF into the aqueous dispersion of TiO2 (Degussa P25) can result in significant enhancement in the photocatalytic degradation (PCD) of organic pollutants, ascribed to the enhanced production of free OH radicals in solution as a result of fluoride displacement of surface hydroxyl groups. In this work, we h...

Layered double hydroxide (LDH) and dodecyl sulfonate-intercalated layered double hydroxide (SDS-LDH) with an Mg/Al ratio of 3.0 were studied as a support of anionic photosensitizer, palladium phthalocyaninesulfonate (PdPcS). The composite clays were synthesized by two different routes: (i) PdPcS intercalation into the clay galleries via direct copr...

Oxidation of inorganic sulfide in water by molecular oxygen was studied under visible light (lambda >= 450 nm) irradiation in the presence of immobilized aluminum tetrasulfophthalocyanine (AlPcTS) on a commercial anionic resin Amberlite IRA 400. The composite catalyst exhibited not only a good capacity for uptake of sulfide ions from water, but als...

This article explores a supported photocatalyst of palladium(II) phthalocyaninesulfonate (PdPcS) onto organoclay for removal of 2,4,6-trichlorophenol (TCP) from water under visible light (lambda > or = 450 nm) irradiation. The composite clay was not only a good sorbent for uptake of TCP from water, but it also exhibited notable activity for TCP oxi...

Bentonite modified with cationic surfactant, cetyltri-methylammonium bromide (CTMA), was an effective sorbent for organic pollutants in water. To make the sorbent recyclable, aluminum phthalocyanine (AIPc), a representative photosensitizer for generation of singlet oxygen, was inserted successfully into the interlamellar space of CTMA-modified bent...

The title complex has been found to exhibit high quantum yield of singlet oxygen generation (0.87 in DMF), and is highly efficient and stable to initiate mineralization of cholorophenols in water under visible light irradiation.