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Photocatalytic hydrogen production from water splitting is of promising potential to resolve the energy shortage and environmental concerns. During the past decade, carbon materials have shown great ability to enhance the photocatalytic hydrogen-production performance of semiconductor photocatalysts. This review provides a comprehensive overview of carbon materials such as CNTs, graphene, C 60 , carbon quantum dots, carbon fibers, activated carbon, carbon black, etc. in enhancing the performance of semiconductor photocatalysts for H 2 production from photocatalytic water splitting. The roles of carbon materials including supporting material, increasing adsorption and active sites, electron acceptor and transport channel, cocatalyst, photosensitization, photocatalyst, band gap narrowing effect are explicated in detail. Also, strategies for improving the photocatalytic hydrogen-production efficiency of carbon-based photocatalytic materials are discussed in terms of surface chemical functionalization of the carbon materials, doping effect of the carbon materials and interface engineering between semiconductors and carbon materials. Finally, the concluding remarks and the current challenges are highlighted with some perspectives for the future development of carbon-based photocatalytic materials. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution under visible light is of great potential for renewable energy development. In this work, unalloyed Au/PtO nanoparticle (NP) co-modified graphitic carbon nitride (g-C 3 N 4 ) photocatalyst is fabricated through a simple photodeposition method. The obtained g-C 3 N 4 composites with co-existed Au and PtO cocatalysts exhibit a considerable enhancement in the photocatalytic hydrogen evolution activity and possess good stability during cycling experiments. The optimal Au–PtO/g-C 3 N 4 photocatalyst shows a H 2 production rate of 16.9 μmol h −1 , which exceeds that of PtO/g-C 3 N 4 and Au/g-C 3 N 4 by a factor of 1.5 and 10.6, respectively. Further characterizations demonstrate that the synergetic action of electron-sink and catalytic effects of PtO along with surface plasmon resonance (SPR) effect of Au NPs, greatly improves the photocatalytic performance of g-C 3 N 4 under visible light. Our study should bring in new insight into the design of effective g-C 3 N 4 -based photocatalysts for solar-to-fuel conversion. [ABSTRACT FROM AUTHOR]

Mesoporous AlOOH with deposited Pt (Pt/AlOOH) catalyst was prepared by combining the microemulsion-assisted synthesis of AlOOH nanoflakes with NaBH 4 -reduction of Pt precursor, and exhibited a remarkable catalytic activity as well as stability for elimination of formaldehyde (HCHO) vapor at room temperature. As compared to Pt deposited on calcined AlOOH (Pt/AlOOH-c), Pt on a commercial Al 2 O 3 (Pt/c-Al 2 O 3 ) and Pt on P25 (Pt/TiO 2 ), the Pt/AlOOH nanoflakes showed the highest catalytic activity toward decomposition of HCHO at room temperature. The excellent performance of Pt/AlOOH nanoflakes could be attributed to the abundance of surface hydroxyls, high dispersion of Pt nanoparticles, excellent adsorption performance of AlOOH, and its high specific surface area and large pore volume. The mechanism of HCHO decomposition was investigated with respect to the behavior of adsorbed intermediates on Pt/AlOOH surface at room temperature using in situ DRIFTS. The result suggests that surface formate is the main reaction intermediate during the HCHO oxidation and it could be directly oxidized to CO 2 in the presence of O 2 . By taking advantage of high adsorption affinity of AlOOH nanoflakes and excellent catalytic activity of Pt nanoparticles toward HCHO it was possible to design a superior nanostructured catalyst for room temperature decomposition of HCHO. This strategy can be also used to fabricate novel nanostructured catalysts for advanced applications such as environmental remediation. [ABSTRACT FROM AUTHOR]

Highlights: [•] CdS with various morphologies prepared by solvothermal method. [•] Solvent influencing morphology and photocatalytic H2-production activity of CdS. [•] The highest H2-production activity observed for CdS nanowires. [Copyright &y& Elsevier]

Highlight: [•] Visible-light-responsive plasmonic Ag@AgCl composite immobilized on titanate nanowire films was prepared. [•] The as-prepared films exhibit higher visible-light photocatalytic performance for the degradation of MO than P25. [•] The samples also show enhanced photocatalytic activity for the degradation of RhB and phenol. [•] Highly reactive species like Cl0 and O2 − is responsible for the photoreactivity. [Copyright &y& Elsevier]

Highlights: [•] The photocatalytic mechanism of visible-light response N S codoped anatase TiO2 was first investigated by the first-principles. [•] The O-poor growth condition is beneficial to the formation of N S codoped anatase TiO2. [•] The bent and flat impurity levels were the separation and combination centers of photogenerated electrons and holes, respectively. [•] The dominant oxidant species during photocatalytic reaction for N S codoped TiO2 was hole and OH radical instead of O2 − ion. [ABSTRACT FROM AUTHOR]

The effects of a room temperature ionic liquid, 1-butyl-3-methylimidazolium terafluoroborate ([Bmim]BF), on the photocatalytic performance of Degussa P25 TiO were investigated. Also, the photocatalysis mechanism was systematically analyzed by conducting different reactive radical trapping experiments. The results showed that photogenerated electrons were the main reactive species involved in the photocatalytic degradation of methyl orange (MO), while •OH radicals and photogenerated holes played an important role in the photocatalytic decomposition of rhodamine B (RhB). The addition of ionic liquid (IL) could slightly enhance the photocatalytic degradation rate of MO because adsorption of [Bmim] ions on the TiO surface not only enhanced traping and transfer of photogenerated electrons, but also facilitated adsorption of negatively charged MO. On the contrary, IL suppressed the degradation rate of RhB because [Bmim] on the TiO surface not only hindered the access of positively charged RhB to TiO, but also restricted the diffusion of positively charged holes to the TiO/solution interface. [ABSTRACT FROM AUTHOR]

Abstract: Graphene, a single layer of graphite, possesses a unique two-dimensional structure, high conductivity, superior electron mobility and extremely high specific surface area, and can be obtained on a large scale at low cost. Thus, it has been regarded as an excellent catalyst support. Recently, graphene-based semiconductor photocatalysts have attracted more attention due to their enhanced photocatalytic activity. In this work, hierarchical macro/mesoporpous TiO2–graphene composites with low loadings (0–0.2wt.%) of graphene were first produced by a simple one-step hydrothermal method using tetrabutyl titanate as the titanium precursor. The prepared composite samples presented enhanced photocatalytic activity in photodegradation of acetone in air. Graphene content exhibited an obvious influence on photocatalytic activity and the optimal graphene addition content was determined. At the optimal graphene concentration (0.05wt.%), the prepared composites showed the highest photocatalytic activity, exceeding that of pure TiO2 and Degussa P-25 by a factor of 1.7 and 1.6, respectively. The enhanced photocatalytic activity is due to graphene as an excellent electron acceptor and transporter, thus reducing the recombination of charge carriers and enhancing the photocatalytic activity. The transient photocurrent response experiment further confirmed the transfer of photogenerated electrons from TiO2 to graphene and the suggested mechanism. [Copyright &y& Elsevier]

Abstract: Semiconductor photocatalysts are of great significance in solar energy conversion and environmental remediation. To overcome serious drawbacks of these materials with respect to narrow light-response range and low quantum efficiency, a variety of strategies have been developed in the past decades to enhance the light harvesting and excitation as well as the charge transfer against recombination. In particular, fluorination of semiconductor photocatalysts can be employed to modify their surface and bulk properties, and consequently, to enhance their photocatalytic performance. This review presents a comprehensive description of the F-mediated synthesis and unique properties of fluorinated semiconductor photocatalysts, in particular titanium dioxide (TiO2). The available strategies for the synthesis of fluorinated photocatalysts include post-synthesis fluorination and in-situ fluorination. Depending on the synthesis route and conditions, it is possible to control the chemical nature of incorporated fluorine (such as adsorbed fluoride and lattice-doped fluorine) and the fluoride-mediated crystal modification and organization, which often results in exceptional surface and bulk physicochemical properties, giving rise to unique photocatalytic properties. Significantly, the surface fluorination induces unusual adsorption behavior and interfacial charge transfer dynamics, directly affecting photocatalytic redox properties of the surface-fluorinated photocatalysts. The lattice fluorine-doping, sole or cooperative with other complementary co-dopants, introduces special localized electronic structures and surface defect states, accounting for the exceptional visible-light photoactivity of the fluorine-doped photocatalysts. Finally, recent advances in the synthesis and properties of fluorinated photocatalysts are summarized along with perspectives on further developments in this area of research. [Copyright &y& Elsevier]

Abstract: Dye-sensitized solar cells (DSSCs) based on anatase TiO2 hollow spheres (TiO2HS)/multi-walled carbon nanotubes (CNT) nanocomposite films are prepared by a directly mechanical mixing and doctor blade method. The prepared samples are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV–vis absorption spectroscopy and N2 adsorption–desorption isotherms. The photoelectric conversion performances of the DSSCs based on TiO2HS/CNT composite film electrodes are also compared with commercial-grade Degussa P25 TiO2 nanoparticles (P25)/CNT composite solar cells at the same film thickness. The results indicate that the photoelectric conversion efficiencies (η) of the TiO2HS/CNT composite DSSCs are dependent on CNT loading in the electrodes. A small amount of CNT clearly enhances DSSC efficiency, while excessive CNT loading significantly lowers their performance. The former is because CNT enhance the transport of electrons from the films to FTO substrates. The latter is due to high CNT loading shielding the visible light from being adsorbed by dyes. [Copyright &y& Elsevier]

Abstract: Hydroxyl radicals ( OH) have been deemed to be the major active species during the photocatalytic oxidation reaction. In this study, OH produced on various semiconductor photocatalysts in aqueous solution under Xenon lamp irradiation was quantitatively investigated by the photoluminescence (PL) technique using coumarin (COU) as a probe molecule. The results indicated that the formation rate of OH on the surface of irradiated commercial Degussa P25 (P25) was much higher than that of other semiconductor. The pH values of the solution and phase structure of TiO2 significantly influenced the production rate of OH. The acidic pH environment of the solutions and bi-phase structure (anatase and rutile) of TiO2 were beneficial to enhancing the formation rate of OH. In addition, the formation rate of OH on anatase TiO2 and P25 was much faster than that of OH on the other semiconductors (such as rutile TiO2, ZnO, WO3, CdS, Bi2WO4 and BiOCl, etc.). A new concept “OH-index” was first proposed to compare photocatalytic activity of photocatalysts, which would provide new insight into the investigation of semiconductor photocatalysts. [Copyright &y& Elsevier]

Abstract: Efficient hydrogen production and decomposition of glycerol were achieved on CuO-modified titania (CuO–TiO2) photocatalysts in glycerol aqueous solutions. CuO clusters were deposited on the titania surface by impregnation of Degussa P25 TiO2 powder (P25) with copper nitrate followed by calcination. The resulting CuO–TiO2 composite photocatalysts were characterized by X-ray diffraction (XRD), UV–visible spectrophotometry, X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The low-power ultraviolet light emitting diodes (UV-LED) were used as the light source for photocatalytic H2-production reaction. A detailed study of CuO effect on the photocatalytic H2-production rates showed that CuO clusters can act as an effective co-catalyst enhancing photocatalytic activity of TiO2. The optimal CuO content was found to be 1.3wt.%, giving H2-production rate of 2061μmolh−1 g−1 (corresponding to the apparent quantum efficiency (QE) of 13.4% at 365nm), which exceeded the rate of pure TiO2 by more than 129 times. The quantum size effect of CuO clusters is deemed to alter its energy levels of the conduction and valence band edges in the CuO–TiO2 semiconductor systems, which favors the electron transfer and enhances the photocatalytic activity. This work shows not only the possibility of using CuO clusters as a substitute for noble metals in the photocatalytic H2-production but also demonstrates a new way for enhancing hydrogen production activity by quantum size effect. [Copyright &y& Elsevier]

Abstract: Preparation of anatase TiO2 with high themal stability is of great importance for its environmental application. In this work, TiOF2 was first synthesized by a simple microwave-assisted hydrothermal route using tetrabutyl titanate and hydrofluoric acid as precursors at 200°C for 20min. Then the resulted precipitates were calcined at different temperatures (300–1000°C) for 2h. The as-prepared samples were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, N2 adsorption–desorption isotherms and X-ray photoelectron spectroscopy. The photocatalytic activity was evaluated using Brilliant Red X3B, an anionic azo dye, as the target organic molecule under UV light irradiation. The results showed that the prepared TiOF2 exhibited weak or no photocatalytic activity. The phase transformation of TiOF2 to anatase TiO2 occurred at about 300°C. The prepared anatase TiO2 from TiOF2 showed very high thermal stability and the anatase-to-rutile phase transformation temperature was up to 1000°C. Fluoride ions played an important role in the improvement of thermal stability of anatase TiO2 by strongly adsorbing on the crystal planes of anatase to stabilize the anatase structure. The 700°C-calcined sample showed the highest photocatalytic activity due to its relative good crystallization and high specific surface areas. [Copyright &y& Elsevier]

Abstract: Trifluoroacetic acid (TFA) modified TiO2 (TFA-TiO2) hollow microspheres were prepared by one-pot hydrothermal treatment of Ti(SO4)2 in the presence of TFA at 180°C for 12h. The prepared samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption–desorption isotherms and Fourier transform infrared. The production rates of surface of UV-illuminated TiO2 were detected by a photoluminescence (PL) method using terephthalic acid (TA) as probe molecule. The photocatalytic activity was evaluated by the photocatalytic decomposition of acetone in air under UV light illumination. The results show that TFA not only induces the formation of hollow microspheres, but also enhances their crystallization. The molar ratios of TFA to Ti(SO4)2 (R) have a great influence on photocatalytic activity. When R is in the range of 0.5–5, the photocatalytic activity of the samples is higher than that of commercial Degussa P25 TiO2 powders (P25) and pure TiO2 samples. At R =2, the photocatalytic activity of the sample reaches the highest and exceeds that of P25 by a factor of more than two times. This is ascribed to the fact that the former has hollow interior and bimodal mesoporous shells enhancing harvesting of light and the transfer and transport of reactant and product molecules, also, the surface-adsorbed TFA can reduce the recombination of photo-generated electrons and holes. [Copyright &y& Elsevier]

Abstract: Highly ordered TiO2 nanotube arrays (TNs) are prepared by electrochemical anodization of titanium foil in a mixed electrolyte solution of glycerol and NH4F and then calcined at various temperatures. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The photocatalytic activity is evaluated by photocatalytic degradation of methyl orange (MO) aqueous solution under UV light irradiation. The production of hydroxyl radicals (e surface of UV-irradiated samples is detected by a photoluminescence (PL) technique using terephthalic acid (TA) as a probe molecule. The transient photocurrent response is measured by several on–off cycles of intermittent irradiation. The results show that low temperatures (below 600°C) have no great influence on surface morphology and architecture of the TNs sample and the prepared TNs can be stable up to ca. 600°C. At 800°C, the nanotube arrays are completely destroyed and only dense rutile crystallites are observed. The photocatalytic activity, formation rate of hydroxyl radicals and photocurrent of the TNs increases with increasing temperatures (from 300 to 600°C) due to the enhancement of crystallization. Especially, at 600°C, the sample shows the highest photocatalytic activity due to its bi-phase composition, good crystallization and remaining tubular structures. With further increase in the calcination temperature from 600 to 800°C, the photocatalytic activity rapidly decreases due to the vanishing of anatase phase, collapse of nanotube structures and decrease of surface areas. [Copyright &y& Elsevier]

Abstract: Bimodal mesoporous TiO2 microspheres with high photocatalytic activity were prepared by a hydrothermal method using titanium sulfate as precursor in the presence of urea. The results indicate that all prepared samples show bimodal pore-size distributions in the mesoporous region: smaller intra-aggregated pores with peak pore diameter of ca. 2nm and larger inter-aggregated pores with peak pore diameter of ca. 12.5nm. The molar ratio of urea to Ti(SO4)2 (R u) has an obvious influence on the morphology, microstructure and photocatalytic activity of TiO2. With increasing R u, specific surface areas and porosity increase, contrarily, the crystallite size and relative anatase crystallinity decrease. The photocatalytic activity first increases with R u. At R u =2.0, the photocatalytic activity reaches the highest and is obviously higher than that of Degussa P25. With further increasing R u, the photocatalytic activity decreases. The formation rate of hydroxyl radicals during photocatalysis has a positive correlation with the photocatalytic activity. [Copyright &y& Elsevier]

Abstract: Fe-doped TiO2 (Fe-TiO2) nanorods were prepared by an impregnating-calcination method using the hydrothermally prepared titanate nanotubes as precursors and Fe(NO3)3 as dopant. The as-prepared samples were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, N2 adsorption–desorption isotherms and UV–vis spectroscopy. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air under visible-light irradiation. The results show that Fe-doping greatly enhance the visible-light photocatalytic activity of mesoporous TiO2 nanorods, and when the atomic ratio of Fe/Ti (R Fe) is in the range of 0.1–1.0%, the photocatalytic activity of the samples is higher than that of Degussa P25 and pure TiO2 nanorods. At R Fe =0.5%, the photocatalytic activity of Fe-TiO2 nanorods exceeds that of Degussa P25 by a factor of more than two times. This is ascribed to the fact that the one-dimensional nanostructure can enhance the transfer and transport of charge carrier, the Fe-doping induces the shift of the absorption edge into the visible-light range with the narrowing of the band gap and reduces the recombination of photo-generated electrons and holes. Furthermore, the first-principle density functional theory (DFT) calculation further confirms the red shift of absorption edges and the narrowing of band gap of Fe-TiO2 nanorods. [Copyright &y& Elsevier]

Abstract: Mesoporous titania nanospheres with high specific surface area and good photocatalytic activity were fabricated on a large scale by a simple spray-hydrolytic method at 90°C. The as-prepared TiO2 spherical powders were characterized by X-ray diffraction, N2 adsorption–desorption measurements, field emission scanning electron microscope, transmission electron microscopy, UV–visible diffuse reflectance spectra and photocurrent measurements. The photocatalytic activity was evaluated by photocatalytic decomposition of toluene in air. The effects of calcination temperatures on the microstructures and photocatalytic activity of the TiO2 powders were investigated and discussed. The results revealed that a large amount of mesoporous titania nanospheres could spontaneously form by self-assembly of countless tiny TiO2 primary nanoparticle during the spray hydrolysis at 90°C. The calcination temperature exhibited a strong effect on the microstructures and photocatalytic activity of the prepared titania. The 400°C-calcined sample showed the highest photocatalytic activity and was about two times higher than that of Degussa P25. At 600°C, the photocatalytic activity decreased because of the destruction of bimodal mesoporous structure of the titania and the drastic decrease of specific surface areas. [Copyright &y& Elsevier]

Abstract: Au–TiO2 nanocomposite microspheres were prepared by hydrothermal treatment of precipitates of tetrabutyl titanate (Ti(OC4H9)4) in a mixed solution of water, ethanol and Au colloid particles at 180°C for 7h. The as-prepared products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen sorption, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and photoluminescence spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation decomposition of formaldehyde in air. The results showed that the presence of nanosized Au particles slightly depressed the grain growth of anatase, resulting in smaller crystallite size and greater specific surface areas. Moreover, the absorbance and photoluminescence of anatase TiO2 was modified by those added Au nanoparticles and an appropriate Au amount in Au–TiO2 nanocomposite microspheres led to increase of band gap, decrease of photoluminescence intensity and prolongation of life of photo-generated electrons and holes. The photocatalytic activity of Au–TiO2 nanocomposite microspheres was obviously higher than that of pure TiO2 microspheres and Degussa P25. When the atomic percentage ratio of Au to Ti was below 0.00425, the apparent reaction rate constants increased. When the atomic percentage ratio of Au to Ti reached 0.00425, the sample displayed the highest photocatalytic activity. [Copyright &y& Elsevier]

Abstract: ZnO micrometer-sized rods with tunable aspect ratios and 3D hollow spherical superstructures are selectively fabricated by a simple poly(sodium 4-styrene-sulfonate) (PSS)-mediated hydrothermal crystallization and assembly strategy. When PSS concentration is relatively low (0–0.5 g L), the aspect ratios of as-obtained microrods steadily decrease with increasing PSS concentration due to the selective adsorption of PSS on the polar ZnO (001) crystal plane. When PSS concentration is relatively high (1 g L), 3D nanosheets-built hollow microspheres form probably due to the organic–inorganic interfacial cooperative assembly. Raman, photoluminescence and UV–vis diffuse reflectance spectra show that the optical properties of as-obtained ZnO microstructures are highly related to their specific morphologies. [Copyright &y& Elsevier]

Abstract: The morphogenesis and phase changes of calcium carbonate in an ethanol/water mixed solvent in the presence of polyelectrolyte poly-(sodium 4-styrene-sulfate) (PSSS) were carefully investigated. The results showed that the ethanol volume content in the mixed solvent, temperature, the molar ratio of [CO3 2−]/[Ca2+] (R), and the concentrations of PSSS and CaCO3 turned out to be important parameters for the control of morphologies and polymorphs of CaCO3. Various morphologies of CaCO3 particles, such as rhombohedras, cubes, flowers, spheres, pancakes, etc. could be obtained dependent on the experimental conditions. Especially, monodispersed spheroid vaterite particles were obtained at the concentration of CaCO3 of 4mM. In addition, pancake-like vaterite particles were synthesized at 100°C. This research may provide a promising route for the selective synthesis of other inorganic materials with different morphologies and polymorphs. [Copyright &y& Elsevier]

Abstract: Novel dendrite-like SnS particles were synthesized for the first time by a facile solvothermal method based on the reaction between tin dichloride dihydrate (SnCl2·2H2O) and thiourea (Tu) in a mixed solvent of ethylenediamine (En) and dodecanethiol (De) at 200°C for 24h. The as-prepared products were characterized by X-ray diffraction and scanning electron microscopy (SEM). The experimental results showed that the concentration of SnCl2·2H2O and the relative volume ratios of En to De played important roles in the formation of unusual dendrite-like SnS architectures. On the basis of the experimental results, it was concluded that the formation of dendrite-like SnS particles was due to the oscillation of the concentration of Sn2+ ions at the vicinity of the growing surfaces, and the consequent periodic growth of the crystals. [Copyright &y& Elsevier]

Abstract: Bi2WO6 hierarchical multilayered flower-like assemblies are fabricated on a large scale by a simple hydrothermal method in the presence of polymeric poly(sodium 4-styrenesulfonate). Such 3D Bi2WO6 assemblies are constructed from orderly arranged 2D layers, which are further composed of a large number of interconnected nanoplates with a mean side length of ca. 50nm. The bimodal mesopores associated with such hierarchical assembly exhibit peak mesopore size of ca. 4nm for the voids within a layer, and peak mesopore size of ca. 40nm corresponding to the interspaces between stacked layers, respectively. The formation process is discussed on the basis of the results of time-dependent experiments, which support a novel ‘coupled cooperative assembly and localized ripening’ formation mechanism. More interestingly, we have noticed that the collective effect related to such hierarchical assembly induces a significantly enhanced optical absorbance in the UV–visible region. This work may shed some light on the design of complex architectures and exploitation of their potential applications. [Copyright &y& Elsevier]

Abstract: Monodispersed BaSO4 micrometer and submicrometer sized particles were produced by a simple precipitation reaction in the presence of poly(methacrylic acid) (PMAA) at the ambient temperature. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electron diffraction (ED) were used to characterize the obtained BaSO4 particles, and polycrystalline nature of the BaSO4 products was revealed. A “polymer–M in situ template” model was proposed to elucidate the formation process of such polycrystalline BaSO4 particles. [Copyright &y& Elsevier]

Abstract: Nanocrystalline anatase TiO2 powder photocatalysts were synthesized by a vapor-thermal method using tetrabutyl titanate as precursor at a temperature range from 120 to 200°C. The as-synthesized products were characterized by X-ray diffraction, N2 adsorption–desorption measurement, transmission electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectra, Raman spectra, and their photocatalytic activity was evaluated by photocatalytic oxidation decomposition of acetone in air. The results showed that reaction temperature greatly affected the microstructures and photocatalytic activity of the samples. With increasing reaction temperature and time, the average crystalline size of TiO2 particles increased and their crystallization enhanced, while the specific surface area of the products decreased. The TiO2 powders obtained at a temperature range from 150 to 200°C for 10h showed good photocatalytic activity and were greatly higher than that of Degussa P-25. [Copyright &y& Elsevier]

Abstract: Bimodal mesoporous anatase-phase TiO2 hollow microspheres are one-pot fabricated by hydrothermal treatment of acidic Ti(SO4)2 solution with NH4F. Fluoride not only induces the outward hollowing of the spherical TiO2 aggregates, but also promotes the crystallization of primary anatase TiO2 nanocrystals, resulting in enlarged crystallite sizes and decreased specific surface areas. The hierarchical mesopores exhibit peak intra-aggregated mesopore sizes of 3–10 nm and peak interaggregated mesopore sizes of 30–50 nm, depending on the specific molar ratio of fluoride to titanium ( R ). The pore volume increases in parallel with the average pore size with increasing R until the collapse of interaggregated pores at . The photocatalytic efficiency in decomposition of gaseous acetone by as-obtained hollow TiO2 microspheres generally exceeds that by Degussa P25 when R is <2. The influence of fluoride on photoactivity are discussed in terms of phase structures and pore structures. [Copyright &y& Elsevier]

Abstract: Hierarchical pagodas and monodispersed quasi-octahedrons of lead tungstate (PbWO4) have been controllably synthesized through an easy mineralization process of preformed PbWO4 suspension under natural conditions. The selective synthesis of PbWO4 pagodas and quasi-octahedrons is achieved in the absence or presence of mixed organic additive polyvinylpyrrolidone and cetyltrimethylammonium bromide. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and Fourier transformation infrared spectroscopy have been used to characterize the obtained PbWO4 products. It is demonstrated that the cooperative effect of polyvinylpyrrolidone and cetyltrimethylammonium bromide is responsible for the morphological transformation of PbWO4 crystals from pagodas to quasi-octahedrons. [Copyright &y& Elsevier]

Hydrogen titanate (H-titanate) nanowires were prepared via a hydrothermal reaction of TiO2 powders (P25) in KOH solutions and then calcined at various temperatures. The phase structure, crystallite size, morphology, specific surface area, and pore structures of the calcined H-titanate nanowires at various temperatures were characterized with field emission scanning electron microscope, X-ray diffraction, transmission electron microscopy and nitrogen adsorption–desorption isotherms, and their photocatalytic activities were evaluated by photocatalytic oxidation of acetone in air. With increasing calcination temperature, the specific surface area and porosity of the calcined samples steadily decreased. At a calcination temperature range of 400–600°C, the calcined H-titanate nanowires showed higher photocatalytic activity than P25 powders for photocatalytic oxidation of acetone. Especially, at 500°C, the calcined H-titanate nanowires showed the highest photocatalytic activity, which exceeded that of P25 by a factor of about 1.8 times. This can be attributed to the synergetic effect of larger specific surface area, higher pore volume and the presence of brookite TiO2. With further increase in the calcination temperature (700–900°C), the photocatalytic activity of the samples decreased obviously owing to the growth of TiO2 crystallites. [Copyright &y& Elsevier]

Abstract: Bimodal nanocrystalline mesoporous TiO2 powders with high photocatalytic activity were prepared by a hydrothermal method using tetrabutylorthotitanate (TiO(C4H9)4, TBOT) as precursor. The as-prepared TiO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption measurements. The photocatalytic activity of the as-prepared TiO2 powders was evaluated by the photocatalytic degradation of acetone (CH3COCH3) under UV-light irradiation at room temperature in air. The effects of hydrothermal temperature and time on the microstructures and photocatalytic activity of the TiO2 powders were investigated and discussed. It was found that hydrothermal treatment enhanced the phase transformation of the TiO2 powders from amorphous to anatase and crystallization of anatase. All TiO2 powders after hydrothermal treatment showed bimodal pore-size distributions in the mesoporous region: one was intra-aggregated pores with maximum pore diameters of ca. 4–8nm and the other with inter-aggregated pores with maximum pore diameters of ca. 45–50nm. With increasing hydrothermal temperature and time, the average crystallite size and average pore size increased, in contrast, the Brunauer-Emmett-Teller (BET) specific surface areas, pore volumes and porosity steadily decreased. An optimal hydrothermal condition (180°C for 10h) was determined. The photocatalytic activity of the prepared TiO2 powders under optimal hydrothermal conditions was more than three times higher than that of Degussa P25. [Copyright &y& Elsevier]

Abstract: Na-free anatase TiO2 film was prepared on soda-lime glass (SL-glass) from a TiF4 aqueous solution upon addition of boric acid at 60°C. It was found that the as-prepared TiO2 film before calcination showed a higher photocatalytic activity than the calcined sample (500°C). This could be attributed to the fact that the calcined TiO2 film contained decent Na+ ions, which was diffused from the SL-glass substrate into the TiO2 film during calcination, resulting in the decrease of photocatalytic activity. [Copyright &y& Elsevier]

Abstract: Highly dispersed TiO2 nanoparticles were successfully synthesized by a wet impregnation method using SBA-15 as hard template for confining the growth of TiO2 nanocrystals, and then calcined at 550 °C in muffle furnace for 2 h. The as-synthesized samples were characterized with Fourier transform infrared spectra (FTIR), Raman spectroscopy, diffuse reflectance UV–visible spectroscopy (UV–vis), powder X-ray diffraction (XRD), small-angle X-ray diffraction (SAXRD), nitrogen adsorption, transmission electron microscopy (TEM) and photoluminescence spectra (PL). It was found that SBA-15 contained abundant silanol groups after removal of triblock copolymers by ethanol extraction and could easily adsorb a great number of titanium alkoxide via chemisorption. After subsequent hydrolysis of the anchored Ti complexes and calcination of the amorphous TiO2, anatase TiO2 nanocrystals with spherical shape and uniform particle diameter of about 6 nm were formed. A blue shift was observed in UV–vis absorption spectra due to the quantum size effect of TiO2 nanoparticles. Moreover, the as-prepared TiO2 nanoparticles showed a high PL intensity due to an increase in the recombination rate of photogenerated electrons and holes under UV light irradiation. [Copyright &y& Elsevier]

Abstract: Highly photoactive nano-sized TiO2 powder photocatalyst was prepared by a hydrothermal method at 180°C for 5h using tetrabutyl titanate (TBOT) as the precursor. The pH values of the starting suspensions were adjusted from 1 to 11 using a 1.0M HCl or 1.0M NH3·H2O solution. The obtained TiO2 powders were characterized with X-ray diffraction (XRD), N2 adsorption–desorption measurement, transmission electron microscopy (TEM), X-ray photoelectron spectra, Fourier transform infrared (FTIR), Raman spectra and UV–vis spectrophotometry. The photocatalytic activity was evaluated by photocatalytic oxidation decomposition of acetone in air. The results showed that the pH values of the solutions obviously influenced the microstructures and photocatalytic activity of the as-prepared TiO2 powders. With increasing pH values, the crystallization enhanced, crystallite size increased and BET specific surface areas decreased. The photocatalytic activity of TiO2 powders prepared at a pH range of 6–9 exceeded that of Degussa P-25 by a factor of more than two times. [Copyright &y& Elsevier]

Abstract: Mesoporous anatase TiO2 nanofibers were prepared by a simple hydrothermal post-treatment of titanate nanotubes. The as-prepared samples were characterized with transmission electron microscopy (TEM), thermogravimetry (TG), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and N2 adsorption–desorption measurement. The photocatalytic activity of the mesoporous TiO2 nanofibers was evaluated by photocatalytic oxidation of acetone in air. The effects of hydrothermal post-treatment time on the structures and photocatalytic activity of the mesoporous TiO2 nanofibers were discussed. The results showed that the photocatalytic activity of the TiO2 nanofibers prepared by this method exceeded that of Degussa P25 when the hydrothermal post-treatment time was kept at 200°C for 3–24h. This could be attributed to the fact that the former had smaller crystallite size, larger specific surface area, and higher pore volume. [Copyright &y& Elsevier]

Abstract: Pure calcite crystal with different morphologies such as wood-block and spherical aggregates were prepared by a precipitation reaction in the presence of citric acid. The as-prepared products were characterized with scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that citric acid obviously influenced the formation of precipitates and the morphology of final products. The formation mechanism of wood-block-like particles was proposed according to theoretical deduction and the proposed growth mode. [Copyright &y& Elsevier]

Abstract: TiO2 powder (P25) was hydrothermally treated in pure water at 150°C for different times. The P25 powders before and after hydrothermal treatment were characterized with XRD, TEM, UV–vis, XPS and nitrogen adsorption–desorption isotherms. The results showed that a small amount of anatase was transformed into rutile phase and more aggregates of the TiO2 crystallites formed after hydrothermal treatment, resulting in the decrease of specific surface area of the TiO2 powders. The photocatalytic activity of the hydrothermally treated P25 powders was obviously higher than that of the P25 powder. This can be attributed to the formation of more hydroxyl groups in the surface of TiO2. The more hydroxyl groups would generate more hydroxyl radicals, enhance the adsorption of O2 molecules and reduce recombination of the photogenerated electrons and holes. Moreover, more hydroxyl was also beneficial to the activation of the rutile phase, leading to an enhanced photocatalytic activity. [Copyright &y& Elsevier]

Abstract: Anatase TiO2 nanoparticles were uniformly coated on the surface of the titanate nanorods using TiF4 and H3BO3 as the precursors via a simple solution route. The prepared samples were characterized with SEM, XRD, TEM, HRTEM and nitrogen adsorption–desorption isotherms and their photocatalytic activities were evaluated by photocatalytic decolorization of methyl orange aqueous solution. The effects of the precursor concentration, deposition time and deposition temperature on the morphology and phase structure of the TiO2 nanoparticle-coated titanate nanorods were investigated. Compared with the titanate nanorods, the novel TiO2 nanoparticle-coated titanate nanorods showed an obvious increase in the specific surface area and pore volume due to the formation of TiO2 nanoparticles (10–50nm) on the surface of the titanate nanorods. Moreover, the TiO2 nanoparticle-coated titanate nanorods, which could be readily separated after photocatalytic reaction, exhibited highly photocatalytic activity for the degradation of methyl orange aqueous solution. [Copyright &y& Elsevier]

Abstract: Titanate nanotubes were prepared via a hydrothermal treatment of TiO2 powders (P25) in a 10M NaOH solution at 150°C for 48h and then calcined at various temperatures. The as-prepared titanate nanotubes before and after calcination were characterized with XRD, TEM, HRTEM, SEM, FESEM, and nitrogen adsorption–desorption isotherms. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic oxidation of acetone in air. The effects of calcination temperature on the phase structure, crystallite size, morphology, specific surface area, pore structures and photocatalytic activity of the titanate nanotubes were investigated. The results indicated that at 400 to 600°C, the calcined nanotube samples showed a higher photocatalytic activity than Degussa P25. Especially, at 400 and 500°C, the photocatalytic activity of the calcined nanotubes exceeded that of P25 by a factor of about 3.0 times. This could be attributed to the fact that the former had a larger specific surface area and pore volume. With further increase in the calcination temperature from 700 to 900°C, the photocatalytic activity of the calcined nanotube samples greatly decreased due to the formation of rutile phase, the sintering and growth of TiO2 crystallites and the decrease of specific surface area and pore volume. [Copyright &y& Elsevier]

Abstract: In this paper, strontium carbonate particles with different morphologies were prepared by a simple precipitation reaction of sodium carbonate with strontium nitrate in the absence and presence of poly-(styrene-alt-maleic acid) (PSMA). The as-prepared products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the concentration of PSMA on the morphologies and phase structures of strontium carbonate particles were investigated and discussed. The results showed that SrCO3 particles with various shapes, such as bundles, dumbbells, irregular aggregates and spheres could be obtained by varying the concentration of PSMA. A schematic illustration was proposed to account for the shape evolution of the as-prepared SrCO3 particles. [Copyright &y& Elsevier]

Abstract: A simple method for preparing highly photoactive nanocrystalline mesoporous N,S-codoped TiO2 powders was developed by hydrolysis of Ti(SO4)2 in a NH3·H2O solution at room temperature. The as-prepared TiO2 powders were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermalgravimetric and differential thermal analysis (TG–DTA), UV–vis diffuse reflectance spectra, N2 adsorption–desorption measurements, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The photocatalytic activity was evaluated for the photocatalytic oxidation of acetone and formaldehyde under UV light and daylight irradiation in air, respectively. The results showed that the as-prepared TiO2 powders exhibited a stronger absorption in the UV–vis light region and a red shift in the band gap transition due to N,S-codoping. The photocatalytic activity of the as-prepared N,S-codoped TiO2 powders at a temperature range of 400–700°C were obviously higher than that of commercial Degussa P25. Especially, the daylight-induced photocatalytic activities of the as-prepared N,S-codoped TiO2 powders were about ten times greater than that of Degussa P25. The high activities of the N,S-codoped TiO2 can be attributed to the results of the synergetic effects of strong absorption in the UV–vis light region, red shift in adsorption edge, good crystallization, large surface area and two phase structures of undoped TiO2 and N,S-codoped TiO2. [Copyright &y& Elsevier]

Abstract: Titanate nanoribbons were prepared via a hydrothermal treatment of rutile-type TiO2 powders in a 10M NaOH solution at 200°C for 48h. The as-prepared titanate nanoribbons were then hydrothermally post-treated at 150°C for 12–36h. The titanate nanoribbons before and after hydrothermal post-treatment were characterized with FESEM, XRD, TEM, UV–VIS and nitrogen adsorption–desorption isotherms. The results showed that the hydrothermal post-treatment not only promoted the phase transformation from titanate to anatase TiO2, but also was beneficial to the removal of Na+ ions remained in the titanate nanoribbons. After hydrothermal post-treatment, the TiO2 samples retained the one-dimensional structure feature of the titanate nanoribbons and showed an obvious increase in the specific surface area and the pore volume. [Copyright &y& Elsevier]

Abstract: A novel and simple method for the synthesis of monodispersed microporous SiO2 microspheres with high specific surface area was developed by hydrolysis of tetraethoxysilane (TEOS) in a water–ethanol mixed solution and using dodecylamine (DDA) as hydrolysis catalyst and template. The as-prepared products were characterized with differential thermal analysis–thermogravimetry, scanning electron microscopy, high-resolution transmission electron microscopy, small angle X-ray diffraction and nitrogen adsorption. The effects of experimental conditions including hydrolysis temperatures, calcination temperature and concentrations of TEOS and DDA on the morphology and pore parameters of the as-prepared SiO2 microspheres were investigated and discussed. The results showed that hydrolysis temperature and concentrations of TEOS and DDA are important parameters for the control of size and morphology of particles. The specific surface area and specific pore volume of the as-prepared SiO2 microspheres increased with increasing DDA concentration and calcination temperature. DDA may act not only as a good hydrolysis catalyst but also as a template for the formation of monodispersed SiO2 microspheres with high specific surface area. This research may provide new insight into the synthesis of monodispersed microporous SiO2 microspheres. [Copyright &y& Elsevier]

Abstract: PbS crystals with various morphologies, as well as PbS aggregates of crystalline subunits were successfully prepared by an aqueous-phased route employing lead nitrate and thioacetamide (TAA) as the reactants, and poly(methacrylic acid) (PMAA), cetyltrimethylammonium bromide (CTAB) and PMAA–CTAB mixed systems as crystal growth modifiers, respectively. The as-prepared products were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that PMAA, CTAB and PMAA–CTAB systems show obvious influence on the crystallization of PbS crystals. Diverse polyhedral PbS crystals, spherical and coral-like aggregates of crystalline subunits of PbS could be prepared in the presence of PMAA or/and CTAB. The concentrations of PMAA or/and CTAB were turned out to be the critical factors to determine the final morphology or aggregation model of PbS crystals. The aggregation mechanisms of PbS crystalline subunits were proposed and discussed. [Copyright &y& Elsevier]

Abstract: Ag–TiO2 multiphase nanocomposite thin films were prepared on quartz substrates by the liquid phase deposition (LPD) method from a mixed aqueous solution of ammonium hexafluouotitanate, silver nitrate and boric acid under ambient temperature and atmosphere followed by calcination at 500°C for 1h. The grain growth of anatase was depressed upon Ag+ doping. However, silver ions not only promoted (or catalyzed) the formation of brookite phase but also reduced the phase transformation temperature of anatase to rutile. With increasing AgNO3 concentration, the transmittance and band gap of the composite thin films decreased; however, the intensity of surface plasmon absorption (SPA) peaks increased and their peak position shifted to a longer wavelength range. When AgNO3 concentration was higher than 0.03M, the prepared samples consisted of anatase, brookite, rutile and metal silver nanocrystal particles, and their grain size ranges were 5–30nm. The photocatalytic activity of the Ag–TiO2 multiphase nanocrystal composite thin films prepared by this method exceeded that of pure TiO2 thin films by a factor of more than 6.3 when AgNO3 concentration was kept in the range of 0.03–0.05. This was attributed to the fact that there were many hetero-junctions, such as anatase/rutile, anatase/brookite, Ag/anatase, Ag/rutile and so on, existed in the Ag–TiO2 multiphase nanocomposite films. [Copyright &y& Elsevier]

Abstract: Calcium oxalate (CaOx) particles with different morphologies and phase structures were prepared by a facile precipitation reaction of sodium oxalate with calcium chloride in the absence and presence of poly(sodium 4-styrene-sulfonate) (PSSS) at different temperatures. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. The influence of experimental conditions including pH, temperature, and concentration of PSSS and CaC2O4 on the morphologies and phase structures of the prepared calcium oxalate particles were investigated. It was found that variations in the concentration of PSSS and CaC2O4, temperature, and pH significantly influenced the crystal structure, morphology, and particle size of the samples. Various crystal morphologies of calcium oxalate, such as plate, leaf-shaped, bipyramid, and cylinder could be fabricated, depending on the experimental conditions. Higher PSSS concentration and reaction temperature favored the formation of metastable calcium oxalate dihydrate (COD) crystals and stable calcium oxalate monohydrate (COM), respectively. Especially, cylinder-shaped CaC2O4 particles were obtained at 80 °C in the presence of PSSS for the first time. This research may provide new insight into understanding and potentially regulating the formation of kidney stones and the control of morphology and phase structures of calcium oxalate particles. [Copyright &y& Elsevier]

Abstract: Bi2WO6 powder photocatalyst was prepared using Bi(NO3)3 and Na2WO4 as raw materials by a simple hydrothermal method at 150°C for 24h, and then calcined at 300, 400, 500, 600 and 700°C for 2h, respectively. The as-prepared samples were characterized with UV-visible diffuse reflectance spectra, fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption–desorption measurement. The photocatalytic activity of the samples was evaluated using the photocatalytic oxidation of formaldehyde at room temperature under visible light irradiation. It was found that post-treatment temperature obviously influenced the visible-light photocatalytic activity and physical properties of Bi2WO6 powders. At 500°C, Bi2WO6 powder photocatalyst showed the highest visible-light photocatalytic activity due to the samples with good crystallization and high BET surface area. [Copyright &y& Elsevier]

Abstract: SiO2/TiO2 composite microspheres with microporous SiO2 core/mesoporous TiO2 shell structures were prepared by hydrolysis of titanium tetrabutylorthotitanate (TTBT) in the presence of microporous silica microspheres using hydroxypropyl cellulose (HPC) as a surface esterification agent and porous template, and then dried and calcined at different temperatures. The as-prepared products were characterized with differential thermal analysis and thermogravimetric (DTA/TG), scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption. The results showed that composite particles were about 1.8μm in diameter, and had a spherical morphology and a narrow size distribution. Uniform mesoporous titania coatings on the surfaces of microporous silica microspheres could be obtained by adjusting the HPC concentration to an optimal concentration of about 3.2mmolL−1. The anatase and rutile phase in the SiO2/TiO2 composite microspheres began to form at 700 and 900°C, respectively. At 700°C, the specific surface area and pore volume of the SiO2/TiO2 composite microspheres were 552 and 0.652mLg−1, respectively. However, at 900°C, the specific surface area and pore volume significantly decreased due to the phase transformation from anatase to rutile. [Copyright &y& Elsevier]

Abstract: A mixed system of poly (styrene-alt-maleic acid) (PSMA) and cetyltrimethylammonium bromide (CTAB) was used as a very effective crystal growth modifier to direct the controlled synthesis of CaCO3 crystals with various morphologies and polymorphs. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. It was found that the concentrations and relative ratios of PSMA and CTAB in the mixed aqueous solution were turned out to be important parameters for the morphology and polymorph of CaCO3 crystals. Various morphologies of CaCO3 crystals, such as hollow microsphere, peanut and so on, were produced depending on the concentrations and relative ratios of PSMA and CTAB. Moreover, the formation mechanisms of CaCO3 crystals with different morphologies were discussed. [Copyright &y& Elsevier]

Abstract: Mesoporous titanium dioxide nanocrystalline powders were synthesized by ultrasonic-induced hydrolysis reaction of tetrabutyl titanate (Ti(OC4H9)4) in pure water without using any templates or surfactants. The as-prepared samples were characterized with X-ray diffraction (XRD) and N2 adsorption–desorption measurements. The photocatalytic activity of the samples was evaluated using the probe reaction: the photocatalytic oxidation of mixture of formaldehyde and acetone at room temperature. It was found that the as-prepared products by the ultrasonic method were composed of anatase and brooktie phases. The photocatalytic activity of the samples prepared by ultrasonic method is higher than that of commercial Degussa P25 and the samples prepared by conventional hydrolysis method. [Copyright &y& Elsevier]

Calcium oxalate (CaOx) particles exhibiting different shapes and phase structures were fabricated by a simple precipitation reaction of sodium oxalate with calcium chloride in the absence and presence of poly-(styrene-alt-maleic acid) (PSMA) as a crystal modifier at room temperature. The as-obtained products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of reaction conditions including pH, [Ca2+]/[C2O42-] ratio and concentration of PSMA and CaC2O4 on the crystal forms and morphologies of the as-obtained calcium oxalate were investigated. The results show that various crystal morphologies of calcium oxalate, such as parallelograms, plates, spheres, bipyramids etc. can be obtained depending on the experimental conditions. Higher polymer concentration favors formation of the metastable calcium oxalate dihydrate (COD) crystals. Lower pH is beneficial to the formation of plate-like CaOx crystals. Especially, the monodispersed parallelogram-like CaOx crystals can be produced by PSMA as an additive at pH 2. PSMA may act as a good inhibitor for urolithiasis since it induces the formation of COD and reduces the particle size of CaOx. This research may provide new insight into the morphological control of CaOx particles and the prevention of urolithiasis. [Copyright &y& Elsevier]

Calcium carbonate particles with various shapes were prepared by the reaction of sodium carbonate with calcium chloride in the absence and presence of a polyacrylic acid (PAA) at 25°C and 80°C, respectively. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. The effects of pH, temperatures, aging time and concentration of PAA and CaCO3 on the crystal form and morphologies of the as-prepared CaCO3 were investigated. The results show that pH, temperatures, concentration of PAA and CaCO3 are important parameters for the control of morphologies of CaCO3. Various crystal morphologies of calcite, such as, plates, rhombohedras, rectangles, ellipsoids, cubes, etc. can be obtained depending on the experimental conditions. Especially, the monodispersed cubic calcite particles can be produced by PAA addition at 80°C. Moreover, higher temperature is beneficial to the formation of monodispersed cubic or rectangular calcite particles. This research may provide new insight into the control of morphologies of calcium carbonate and the biomimetic synthesis of novel inorganic materials. [Copyright &y& Elsevier]