What is the band gap of TiO2?

TiO2 anatase plays a central role in energy and environmental research. A major bottleneck toward developing artificial photosynthesis with TiO2 is that it only absorbs ultraviolet light, owing to its large bandgap of 3.2 eV.

Why is mesoporous TiO2?

Since then, mesoporous TiO2 has attracted more and more interest due to its great advantages, including good chemical and physical properties, non-toxicity and good biocompatibility, excellent photoelectric performance, as well as their broad applications in photocatalysis, energy and biology.

What is mesoporous TiO2?

Mesoporous materials are materials with high surface area and intrinsic porosity, and therefore have attracted great research interest due to these unique structures. Mesoporous titanium dioxide (TiO2) is one of the most widely studied mesoporous materials given its special characters and enormous applications.

Why TiO2 is N type semiconductor?

The oxygen vacancies act as electron donors, thus TiO2-x is an n-type semiconductor, in contrast with p-type semiconductors which contain electron acceptors and where the charge carriers are holes rather than electrons [23].

What is the band gap of rutile?

Rutile was measured to have a larger band gap (3.3 − 3.5 eV) than is usually found in the literature.

Is tio2 a porous material?

3.1. SEM images of NC and AC before and after deposition of TiO2 are shown in Figure 2. From the micrograph, it is clear that the surface morphologies of NC (Figure 2(a)) and AC (Figure 2(b)) have a porous nature with uniform structures. After impregnation process, the TiO2 particles are found to be well-dispersed.

What is mesoporous structure?

A mesoporous material (or super nanoporous) is a nanoporous material containing pores with diameters between 2 and 50 nm, according to IUPAC nomenclature.

Is TiO2 n-type or p-type?

n-type semiconductor
In general, TiO2 is intrinsically an n-type semiconductor but can be doped to have p-type semiconductivity. This provides a very important opportunity to fabricate all-transparent homojunction devices for light harvesting and energy storage.

Is TiO2 ap or n-type semiconductor?

Non-metal doped TiO2 generally is P-type.

What is the band gap of ZnO?

The estimated optical band gap of ZnO is found to be 3.63 eV which also clearly indicates the presence of blueshift at a growth temperature of 60 °C.

What is direct and indirect band gap?

If the k-vectors are different, the material has an “indirect gap”. The band gap is called “direct” if the crystal momentum of electrons and holes is the same in both the conduction band and the valence band; an electron can directly emit a photon.

What size is mesoporous?

between 2 nm and 50 nm
Mesoporous materials are defined as organized structures with pore diameters ranging between 2 nm and 50 nm.