Liqun Mao

A general method to synthesize a family of mesoporous silica nanoparticles less than 100 nm and their applications in anti-reflective/fogging coating

Recent advances in strategies for synthesizing mesoporous silica particle (MSN) have enabled the precise control of its morphology, size, and composition which afford the applications in drug delivery and heterogeneous catalysis. Especially for drug delivery, the size of MSNs <100xa0nm is a prerequisite allowing for hemolysis effect. However, a general method for the synthesis of MSNs with uniform size distribution below 100xa0nm still remains challenging. Herein, a general method was developed to synthesize a family of aqueous colloidal MSNs with uniform size <100xa0nm using small organic amines (SOAs) or nitrogen-containing heterocyclic compounds (NCHCs) as alkaline catalysts in the presence of cationic quaternary ammonium salts as organic templates. The size of MSNs can be easily adjusted within the range from 28 to 100xa0nm by the cooperative effect of the mixed alkaline catalysts or using different quaternary ammonium surfactants as templates. Also, texture properties of MSNs including pore diameter and surface area were controlled by selecting different kinds of SOAs or NCHCs. Based on the low refractive index of MSNs, these as-prepared MSNs serve as building blocks and afford an anti-reflective/fogging coating on glass slide through a facile dip-coating method.

Pt–Nix alloy nanoparticles: a new strategy for cocatalyst design on a CdS surface for photo-catalytic hydrogen generation

Solar photocatalytic water splitting for the production of hydrogen has been a core aspect for decades. A highly active and durable photocatalyst is crucial for the success of the renewable hydrogen economy. To date, the development of highly effective photocatalysts has been seen by the contemporary research community as a grand challenge. Thus, herein we put forward a sincere attempt to use a Pt–Nix alloy nanoparticle (NP) cocatalyst loaded CdS photocatalyst ((Pt–Nix)/CdS) for photocatalytic hydrogen production under visible light. The Pt–Nix alloy NP cocatalyst was synthesized using a one-pot solvothermal method. The cocatalyst nanoparticles were deposited onto the surface of CdS, forming a Pt–Nix/CdS photocatalyst. Photocatalytic hydrogen production was carried out using a 300 W Xe light equipped with a 420 nm cut-off filter. The H2 evolution rate of the Pt–Ni3/CdS photocatalyst can reach a value as high as 48.96 mmol h−1 g−1 catalyst, with a quantum efficiency of 44.0% at 420 nm. The experimental results indicate that this Pt–Ni3/CdS photocatalyst is a prospective candidate for solar hydrogen generation from water-splitting.

Heterogeneous liquid phase oxidation of ethylbenzene to acetophenone with graphene carbon-based catalyst

The series of graphene materials and N-doped graphene materials were successfully synthesized and improved by high-temperature treatment with trace iron oxide. XRD, Raman, FT-IR, TEM and XPS were employed for these catalysts. The catalytic performance of these catalysts was investigated in the selective oxidation of ethylbenzene with tert-butyl hydroperoxide as oxidant. The impacts of temperature, mass of catalysts, reaction time and oxidants on the selective oxidation of ethylbenzene were also investigated. The N-doped graphene materials exhibit greatly remarkable catalytic performance than others. The conversion of ethylbenzene is more than 90% and the selectivity of acetophenone is more than 95% at 353xa0K. Graphene can be used as catalyst owing to its unique structures and chemical properties. The characterization tests show that the doping of N atoms can create more defects and more active sites in the N-doped graphene materials which could greatly improve the catalytic performance. Furthermore, such cost-effective graphene-based catalysts possess good stability and could be reused at least five times without remarkable loss of the catalytic activity.