A facile polyol-mediated solvothermal method was developed to fabricate BiOCl hierarchical nanostructures (HNs) with controllable morphologies. The obtained BiOCl hierarchical nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflection spectroscopy (DRS) and nitrogen adsorption. The BiOCl hierarchical nanostructures (HNs) with ellipsoid-like, sphere-like and flower-like morphologies were constructed of intercrossed nanoflakes or nanosheets. The polyols played significant roles in the fabrication of BiOCl hierarchical nanostructures, which functioned as solvents, reducing and morphology-directing agents. Importantly, the BiOCl hierarchical nanostructures exhibited excellent shape-dependent visible-light-driven photocatalytic activities for Rhodamine B (RhB) degradation, which was much higher than that of 2D BiOCl nanosheets, nanoplates, commercial BiOCl and TiO 2 (anatase). The highly enhanced photocatalytic activities could be ascribed to the contributions of their hierarchical nanostructures, large BET surface areas, strong adsorption capacities and superhydrophilic properties.
A facile and green template-free hydrothermal method was conducted to controllably synthesize spinel type cobalt oxides (Co 3 O 4 ) with cube, truncated octahedron and octahedron morphologies. The catalytic performance over various shapes of catalysts was investigated towards CO oxidation. Among of them, the Co 3 O 4 cube performs the best catalytic activity, which can even be comparable to those of certain noble metal catalysts. The phenomenon might be ascribed to the synergistic effects of exposed Co 3+ active sites and surface oxygen distribution on the surface of the catalyst. The results may provide significant insights for the fabrication of metal oxide catalysts for CO oxidation .
Hui Xie,Yajuan Zhao,Yong Tian,Xiufang Wang,Mingfang Yan
Owing to the shallow understanding of the formation mechanism of ordered mesoporous carbon nanoparticles (OMCNs), there are still many obstacles to the synthesis of OMCNs with controllable morphology by a simple and efficient method. Herein, we first propose a universal mechanism for OMCNs formation, that is, the composite micelle units self-assembly mechanism. Under the guidance of this mechanism, the inexpensive F127 was selected as the soft template, resorcinol and hexamethylenetetramine were used as the carbon source, and a series of dispersions were synthesized for the first time under acidic condition by the one-step aqueous solution method. Interestingly, OMCNs could be transformed from spherical to rhombic dodecahedron by adjusting the amount of F127. Moreover, the particle size of the obtained polymer nanoparticles (PNs) exhibited a linear relationship with the amount of F127 in a wide range ( W F127 = 0.25 g–0.70 g), and the linear equation is y = − 1523.6 x + 1055.8 (R 2 = 0.99), which can realize the customized synthesis of PNs. As a demonstration of their versatility, a simple and novel method was developed to prepare magnetic Fe-OMCNs by iron doping of PNs by oxidation reaction of iron. These findings have pioneering implications for promoting the development of OMCNs.
Xuan Cai,Zhenxing Wang,Huanhuan Zhang,Yufei Li,Kaicha Chen,Hongli Zhao,Minbo Lan
Transition metal phosphates have shown great potential as nanozymes for selective detection of reactive oxygen species (ROS), but its application has been hindered by the complicated synthesis and difficulty in shape and size control. Herein, we present a facile method to fabricate transition metal phosphates by using hollow carbon structures as substrates. Manganese phosphate is a typical Nanozyme used in this design and the shape and size of the Mnx(PO4)y layer can be efficiently controlled by altering the carbon substrates. Characterization demonstrated that Mnx(PO4)y layer modified hollow carbon sphere (Mn-MPSA-HCS) and hollow carbon cubic (Mn-MPSA-HCC) were successfully prepared and used as nanozymes for superoxide detection. The established electrochemical sensor was employed in the online monitoring of drug stimulated superoxide anions released from cancer cells. This method can be adapted as a general way to prepare transition metal phosphate layers with various controllable shapes and sizes as nanozymes for different uses in the future.
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