Nanoscale hydroxyapatite particles for bone tissue engineering

Since the early development of this technology in the 1970s, TiO2 constitutes the archetypical photocatalyst due to its relatively high efficiency, low cost and availability. However, during the last decade a considerable number of new photocatalytic materials, either semiconductor or not, have been proposed as potential substitutes of TiO2, particularly in the case of solar applications, for which this standard photocatalyst is not very suitable because of its wide band gap. Semiconductors based on cations with d0 configuration such Ta5+ or Nb5+, as well as oxides or nitrides of d10 elements such as Bi3+, In3+ or Ga3+ are among the most successful novel photocatalysts, but non-semiconductor solids like cation-interchanged zeolites also produce interesting results. In addition, some classical semiconductors like ZnO or CdS, initially discarded as a consequence of their poor stability under irradiation, have been reconsidered as feasible photocatalysts for particular applications. This growing body of data requires new analysis of the challenges and opportunities facing photocatalysis in order to assess which of the photoactive materials are best for each particular application. In this review, we summarize, with an historical perspective, the main achievements obtained with photocatalyst alternatives to TiO2 in the three main niches for this technology: water splitting for hydrogen production, decontamination and disinfection processes, and organic synthesis.

Development of alternative photocatalysts to TiO2: Challenges and opportunities

Synthesis methods for nanosized hydroxyapatite with diverse structures.

This Feature Article gives an overview of microwave-assisted liquid phase routes to inorganic nanomaterials. Whereas microwave chemistry is a well-established technique in organic synthesis, its use in inorganic nanomaterials' synthesis is still at the beginning and far away from having reached its full potential. However, the rapidly growing number of publications in this field suggests that microwave chemistry will play an outstanding role in the broad field of Nanoscience and Nanotechnology. This article is not meant to give an exhaustive overview of all nanomaterials synthesized by the microwave technique, but to discuss the new opportunities that arise as a result of the unique features of microwave chemistry. Principles, advantages and limitations of microwave chemistry are introduced, its application in the synthesis of different classes of functional nanomaterials is discussed, and finally expected benefits for nanomaterials' synthesis are elaborated.

Microwave chemistry for inorganic nanomaterials synthesis

Zero-dimensional, one-dimensional, two-dimensional and three-dimensional nanostructured materials for advanced electrochemical energy devices

Rapid formation of hydroxyapatite nanostructures by microwave irradiation

Hydrothermal synthesis and photocatalytic properties of bismuth molybdate materials

Hydroxyapatite (HAp) nanorods, bowknot-like nanostructures and flower-like architectures have been directly synthesized and assembled under microwave irradiation without the help of any templates. The uniform nanorods present an average diameter of about 40 nm and a length of up to about 400 nm. The as-prepared bowknot-like nanostructures consist of sword-like HAp nanorods with a typical width of 150 nm and lengths up to 1–2 µm. The flower-like architectures are composed of leaf-like flakes with typical diameters of 150–200 nm and lengths up to 1–2 µm. The SAED and HRTEM experiments imply that the sword-like HAp nanorods and leaf-like flakes are single crystalline in nature and preferentially grow along the [001] direction. It is found that the pH value and the complex reagent EDTA play important roles in synthesis of the final HAp nanostructures. The possible mechanism is discussed for the formation of the HAp nanostructures in the presence of EDTA under microwave irradiation.

https://iopscience.iop.org/article/10.1088/0957-4484/16/1/017/pdf

Self-assembly of hydroxyapatite nanostructures by microwave irradiation

Preparation and photocatalytic properties of CdS/La2Ti2O7 nanocomposites under visible light

Nanosized Y 2 Sn 2 O 7 powder photocatalysts with different particle sizes were synthesized through the low temperature hydrothermal method by using different organic agents. The samples were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), surface area and porosity analyzer, and ultraviolet–visible (UV–vis) spectroscopes. Photocatalytic measurements showed Y 2 Sn 2 O 7 nanocrystals with about 10 nm particle sizes possess superior photocatalytic properties in water purification and may find potential application in related fields.

KunWei Li

Papers

Rapid formation of hydroxyapatite nanostructures by microwave irradiation

Hydrothermal synthesis and photocatalytic properties of bismuth molybdate materials

Self-assembly of hydroxyapatite nanostructures by microwave irradiation

Preparation and photocatalytic properties of CdS/La2Ti2O7 nanocomposites under visible light

Hydrothermal preparation and photocatalytic properties of Y2Sn2O7 nanocrystals