Effects of crystal structure and composition on the photocatalytic performance of Ta–O–N functional materials

2018 ◽  
Vol 20 (17) ◽  
pp. 12005-12015 ◽  
Author(s):  
Qing-Lu Liu ◽  
Zong-Yan Zhao ◽  
Jian-Hong Yi
Keyword(s):  
Crystal Structure ◽  
Band Gap ◽  
Photocatalytic Performance ◽  
Electronic States ◽  
Functional Materials ◽  
Band Edge ◽  
Suitable Candidate ◽  
Atomic Core ◽  
Band Edge Position

In Ta–O–N functional materials, the interaction between atomic core and valence electronic states, and the overlapping between valence electronic states mainly influence the band gap and the band edge position. According to the requirements, Ta3N5 and TaON are suitable candidate materials for efficient photocatalyst.

Electronic properties of red and black phosphorous and their potential application as photocatalysts

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 80872-80884 ◽  
Author(s):  
Kaining Ding ◽  
Lili Wen ◽  
Shuping Huang ◽  
Yulu Li ◽  
Yongfan Zhang ◽  
...  
Keyword(s):  
Visible Light ◽  
Band Gap ◽  
Electronic Properties ◽  
Potential Application ◽  
Separation Efficiency ◽  
Charge Carriers ◽  
Band Edge ◽  
Strong Response ◽  
Black Phosphorous ◽  
Band Edge Position

The promising potential of monolayerrPandbPas photocatalysts was identified, due to their suitable band gap, appropriate band edge position, higher mobility and separation efficiency of charge carriers, and strong response to visible light.

Carbon-Dot-Based Heterojunction for Engineering Band-Edge Position and Photocatalytic Performance

Small ◽  
2018 ◽  
Vol 14 (44) ◽  
pp. 1803447 ◽  
Author(s):  
Shengliang Hu ◽  
Wenliang Yang ◽  
Ning Li ◽  
Huiqi Wang ◽  
Jinlong Yang ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Band Edge ◽  
Carbon Dot ◽  
Band Edge Position

Tailored Electronic Band Gap and Valance Band Edge of Nickel Oxide via p-Type Incorporation

2021 ◽  
Vol 125 (13) ◽  
pp. 7495-7501
Author(s):  
Gang Wang ◽  
Jinju Zheng ◽  
Boyi Xu ◽  
Chaonan Zhang ◽  
Yue Zhu ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Band Gap ◽  
Band Edge ◽  
Electronic Band ◽  
Electronic Band Gap ◽  
P Type

A simple tactic synthesis of hollow porous graphitic carbon nitride with significantly enriched photocatalytic performance

2021 ◽  
Author(s):  
Vellaichamy Balakumar ◽  
Manivannan Ramalingam ◽  
Chitiphon Chuaicham ◽  
KARTHIKEYAN SEKAR ◽  
K. Sasaki
Keyword(s):  
Crystal Structure ◽  
Surface Area ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Porous Graphitic Carbon ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Modified Surface

Hollow porous graphitic carbon nitride (porous CN) was synthesized via a simple tactic method, and the resulting porous CN showed an effectively modified surface area, crystal structure and enhanced photocatalytic...

Study of the crystal structure, band gap and dispersion evolution in titanium oxide thin films

2013 ◽  
Vol 210 (11) ◽  
pp. 2374-2378 ◽  
Author(s):  
Fan Zhang ◽  
Rong-Jun Zhang ◽  
Yu-Xiang Zheng ◽  
Zi-Jie Xu ◽  
Dong-Xu Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Band Gap ◽  
Titanium Oxide ◽  
Oxide Thin Films

Photoelectrochemical Properties of Alkali-treated Sodium Titanate Nanorods

2015 ◽  
Vol 1784 ◽  
Author(s):  
Mingu Kim ◽  
Gwanghyo Choi ◽  
Daeheung Yoo ◽  
Kwangmin Lee
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Band Gap ◽  
Heat Treatment Temperature ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Band Gap Energy ◽  
Treatment Temperature ◽  
Photoelectrochemical Properties ◽  
Gap Energy

ABSTRACTThe band gap energy of the TiO2 photocatalytic is high at 3.2 eV. Ultraviolet (UV) light irradiation (<388nm) is required for the photocatalytic application. The lowering the band gap energy of TiO2 and enlarging light absorbing area are effective ways to enhance the efficiency of photocatalytic activity. Furthermore, the morphology and crystal structure of nanosized TiO2 considerably influences its photocatalytic behavior.In this study, sodium titanate nanorods were formed using an alkali-treatment and were heat treated at different temperatures. The photoelectrochemical properties of sodium titanate nanorods was measured as a function of heat treatment temperature. The nanorods were prepared on the surface of Ti disk with a diameter of 15mm and a thickness of 3mm. Ti disk was immersed in 5 M NaOH aqueous solution at a temperature of 60 °C for 24 h. Morphology of sodium titanate nanorods was observed using FE-SEM. Crystal structure of sodium titanate nanorods was analyzed using X-ray diffractometer. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) was used to evaluate photoelectrochemical properties of sodium titanate nanorods. The thin amorphous sodium titanate layer was formed during alkali-treatment. The sodium titanate layer was changed to nanorods after heat treatment at a temperature of 700 °C. The thickness and length of sodium titanate nanorods obtained at 700 °C were around 100 nm and 1μm, respectively. The crystal structure of sodium titanate was identified with Na2Ti6O13. Above 900 °C, the morphology of nanorods changed to agglomerated shape and the thickness of nanorods increased to 1 μm. The lowest value of PL was obtained at a temperature of 700 °C, while nonalkali treated specimen showed the highest value of PL. EIS revealed that polarization resistance at interface between sodium titanate nanorods and electrolyte was increased with increasing heat treatment temperature.

Ultrafast Carrier Dynamics, Optical Amplification, and Lasing in Nanocrystal Quantum Dots

MRS Bulletin ◽  
2001 ◽  
Vol 26 (12) ◽  
pp. 998-1004 ◽  
Author(s):  
Victor I. Klimov ◽  
Moungi G. Bawendi
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Electronic States ◽  
Three Dimensions ◽  
Band Edge ◽  
Lasing Threshold ◽  
Wide Energy Range ◽  
Band Edge Emission ◽  
Edge States

Semiconductor materials are widely used in both optically and electrically pumped lasers. The use of semiconductor quantum wells (QWs) as optical-gain media has resulted in important advances in laser technology. QWs have a two-dimensional, step-like density of electronic states that is nonzero at the band edge, enabling a higher concentration of carriers to contribute to the band-edge emission and leading to a reduced lasing threshold, improved temperature stability, and a narrower emission line. A further enhancement in the density of the band-edge states and an associated reduction in the lasing threshold are in principle possible using quantum wires and quantum dots (QDs), in which the confinement is in two and three dimensions, respectively. In very small dots, the spacing of the electronic states is much greater than the available thermal energy (strong confinement), inhibiting thermal depopulation of the lowest electronic states. This effect should result in a lasing threshold that is temperatureinsensitive at an excitation level of only 1 electron-hole (e-h) pair per dot on average. Additionally, QDs in the strongconfinement regime have an emission wavelength that is a pronounced function of size, adding the advantage of continuous spectral tunability over a wide energy range simply by changing the size of the dots.

scholarly journals Defects in SiC for Quantum Computing

MRS Advances ◽  
2019 ◽  
Vol 4 (40) ◽  
pp. 2217-2222
Author(s):  
Renu Choudhary ◽  
Rana Biswas ◽  
Bicai Pan ◽  
Durga Paudyal
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Density Functional ◽  
Single Photon ◽  
Band Edge ◽  
Valence Band Edge ◽  
Dangling Bonds ◽  
Defect Levels ◽  
Formation Energies ◽  
Qubit Operation

AbstractMany novel materials are being actively considered for quantum information science and for realizing high-performance qubit operation at room temperature. It is known that deep defects in wide-band gap semiconductors can have spin states and long coherence times suitable for qubit operation. We theoretically investigate from ab-initio density functional theory (DFT) that the defect states in the hexagonal silicon carbide (4H-SiC) are potential qubit materials. The DFT supercell calculations were performed with the local-orbital and pseudopotential methods including hybrid exchange-correlation functionals. Di-vacancies in SiC supercells yielded defect levels in the gap consisting of closely spaced doublet just above the valence band edge, and higher levels in the band gap. The divacancy with a spin state of 1 is charge neutral. The divacancy is characterized by C-dangling bonds and a Si-dangling bonds. Jahn-teller distortions and formation energies as a function of the Fermi level and single photon interactions with these defect levels will be discussed. In contrast, the anti-site defects where C, Si are interchanged have high formation energies of 5.4 eV and have just a single shallow defect level close to the valence band edge, with no spin. We will compare results including the defect levels from both the electronic structure approaches.

Quantum dots in photocatalytic applications: efficiently enhancing visible light photocatalytic activity by integrating CdO quantum dots as sensitizers

2017 ◽  
Vol 19 (36) ◽  
pp. 24915-24927 ◽  
Author(s):  
A. H. Reshak
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Optical Band Gap ◽  
Visible Light Active ◽  
Photocatalytic Applications ◽  
Visible Light Photocatalytic

The amalgamation of a wide optical band gap photocatalyst with visible-light-active CdO quantum dots (QDs) as sensitizers is one of the most efficient ways to improve photocatalytic performance under visible light irradiation.

Sign in / Sign up

Export Citation Format

Share Document