scholarly journals SrTiO3 nanocubes doped with ir as photocatalytic system for enhancing H2 generation from water splitting

2020 ◽  
Vol 23 (3) ◽  
pp. First
Author(s):  
Ton Nu Quynh Trang ◽  
Tieu Tu Doanh ◽  
Do Thanh Sinh ◽  
Vu Thi Hanh Thu
Keyword(s):  
Energy Gap ◽  
Band Gap Energy ◽  
H2 Production ◽  
H2 Evolution ◽  
H2 Generation ◽  
Photocatalytic System ◽  
H2 Performance ◽  
Visible Irradiation ◽  
Photocatalytic Reactions

Designing an effective photocatalyst for hydrogen (H2) performance under visible irradiation with a decrease the band gap energy of semiconductor has been considered as an essential aspect in boosting the performance of photocatalytic reactions. Herein, we focus on evaluating the role of doping with Ir into SrTiO3 structure fabricated by hydrothermal method for H2 generation. The crystalline characteristics the Ir-SrTiO3 photocatalyst were carried out via XRD and FE-SEM. The chemical composition and the optical properties of the Ir-SrTiO3 were classified by EDX and UV-Vis spectra, respectively. The results showcased that the dramatically improved absorbing performances of Ir/SrTiO3 specimen could be governed by the presence of Ir impurity states in the forbidden energy gap causing a decrease in energy gap of SrTiO3. This work also revealed that Ir doped into SrTiO3 exhibited excellent photocatalytic H2 evolution compared with pristine SrTiO3 (~454 and ~325 mmol.h-1.g-1 H2 production under UV and visible light irradiation, respectively). A rational photocatalytic mechanism is projected to be able provide significant awareness for further research.

scholarly journals Pt Deposites on TiO2 for Photocatalytic H2 Evolution: Pt Is Not Only the Cocatalyst, but Also the Defect Repair Agent

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1047 ◽  
Author(s):  
Zhan Shu ◽  
Yandi Cai ◽  
Jiawei Ji ◽  
Changjin Tang ◽  
Shuohan Yu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Charge Separation ◽  
H2 Production ◽  
H2 Evolution ◽  
X Ray ◽  
Production Activity ◽  
Defect Repair ◽  
New Perspective ◽  
Photocatalytic H2 Evolution

Pt, as a common cocatalyst, has been widely used in photocatalytic H2 evolution. However, the specific role of Pt in photocatalytic H2 evolution has not been thoroughly studied. In this paper, by employing three Pt sources with different charges (positive, negative and neutral), we systematically studied the charge effect of Pt sources on photocatalytic H2 evolution via TiO2 catalyst. According to the results of Raman, X-ray photoelectron spectroscopy (XPS), recycle experiments and photocurrent characterizations, it was found that TiO2 would produce electropositive defects during photocatalytic H2 evolution, inevitably leading to the decline of H2 production activity. Thanks to the electrostatic interaction, the electronegative Pt source not only promoted charge separation, but preferential deposited on electropositive defects, which acted as the defect repair agent, and thus resulted in the increased photocatalytic stability. This work may provide a new perspective for enhancing photocatalytic stability of hydrogen production.

scholarly journals Structural, Optical and Photocatalytic Characterization of ZnxCd1−xS Solid Solutions Synthetized Using a Simple Ultrasonic Radiation Method

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5603
Author(s):  
Luis Fernando Morelos Medina ◽  
Rufino Nava ◽  
María de los Ángeles Cuán Hernández ◽  
Omar Said Yáñez Soria ◽  
Bárbara Pawelec ◽  
...  
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Catalyst Activity ◽  
Band Gap Energy ◽  
H2 Production ◽  
Catalyst Characterization ◽  
H2 Evolution ◽  
Ultrasonic Radiation ◽  
Radiation Method ◽  
Negative Effect

A simple ultrasonic radiation method was employed for the preparation of zinc and cadmium sulfide solid solution (ZnxCd1−xS; x = 0–0.25 wt.%) with the aim to investigate its efficiency for H2 production via a visible light-driven water-splitting reaction. The catalyst characterization by X-ray diffraction confirmed the formation of solid solution (ZnxCd1−xS) between CdS and ZnS phases. All catalysts exhibited hierarchical morphology (from SEM and TEM) formed by aggregated nanoparticles of ZnxCd1−xS solid solution with crystals showing mainly (111) planes of cubic CdS phase. The crystal size linearly decreased with an increase in Zn incorporation in the crystal lattice (from 4.37 nm to 3.72 nm). The ZnxCd1−xS photocatalysts showed a gradual increase in the H2 evolution, with an increase in the Zn concentration up to 0.2 wt.% making the most effective Zn0.2Cd0.8S catalyst toward H2 production. From the catalyst activity–structure correlation, it has been concluded that the twin-like CdS structure, the (111) plane and specific morphology are the main factors influencing the catalyst effectivity toward H2 production. All those factors compensated for the negative effect of an increase in band gap energy (Ebg) after ZnS incorporation into solid solution (from 2.21 eV to 2.34 eV). The effect of the catalyst morphology is discussed by comparing H2 evolution over unsupported and supported Zn0.2Cd0.8S solid solutions.

Solar-light responsive efficient H2 evolution using a novel ternary hierarchical SrTiO3/CdS/carbon nanospheres photocatalytic system

2021 ◽  
Author(s):  
Saikumar Manchala ◽  
Ambedkar Gandamalla ◽  
Vempuluru Navakoteswara Rao ◽  
Shankar Muthukonda Venkatakrishnan ◽  
Vishnu Shanker
Keyword(s):  
Solar Light ◽  
H2 Evolution ◽  
Carbon Nanospheres ◽  
Photocatalytic System

A renewable photocatalytic system with dramatic photocatalytic activity for H2 evolution and constant light energy utilization: Eosin Y sensitized ZnWO4 nanoplates loaded with CuO nanoparticles

2021 ◽  
Author(s):  
Xiaoluo Bao ◽  
Xiaokun Wang ◽  
Xiangqing Li ◽  
Lixia Qin ◽  
Taiyang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Light Intensity ◽  
Incident Light ◽  
Cuo Nanoparticles ◽  
Energy Utilization ◽  
Limited Attention ◽  
Eosin Y ◽  
H2 Evolution ◽  
Incident Light Intensity ◽  
Photocatalytic System

It is necessary for the commercialization of sunlight-driven H2 evolution to develop an efficient photocatalytic system whose energy utilization is independent on incident light intensity. Unfortunately, limited attention has been...

CdSe Quantum Dots/White Graphene Hexagonal Porous Boron Nitride Sheet (h-PBNs) Heterostructure Photocatalyst for Solar Driven H2 Production

2021 ◽  
Author(s):  
Raheman Shakeelur ◽  
Rupali S. Mane ◽  
Higgins Wilson ◽  
Neetu Jha
Keyword(s):  
Active Site ◽  
Charge Separation ◽  
High Surface ◽  
High Surface Area ◽  
H2 Production ◽  
H2 Evolution ◽  
The World ◽  
2D Nanomaterials ◽  
White Graphene ◽  
Photogenerated Charge Separation

In the world of photocatalytic hydrogen (H2) evolution two-dimensional (2D) nanomaterials have attracted widespread attention owing to their high surface area, abundant active site, and excellent photogenerated charge separation properties....

H2/O2 Cycles: Thermodynamic Potentialities and Limits

2003 ◽  
Author(s):  
M. Gambini ◽  
G. L. Guizzi ◽  
M. Vellini
Keyword(s):  
Production Systems ◽  
Renewable Energy Sources ◽  
H2 Production ◽  
Thermodynamic Cycles ◽  
A Value ◽  
Overall Performance ◽  
Definition Of ◽  
Working Parameters ◽  
O2 Production

In this paper, the thermodynamic potentialities and limits of the H2/O2 cycles are investigated. Starting from the conventional gas turbine and steam turbine technology, the paper qualitatively tackles problems related to a change of oxidizer and fuel: from these considerations, an internal combustion steam cycle (ICSC) is analyzed where steam, injected in the combustion chamber together with oxygen and hydrogen, is produced in a regenerative way and plays the important role of inert. A proper parametric analysis is then performed in order to evaluate the influence of the main working parameters on the overall performance of H2/O2 cycles. All the results are carried out neglecting the energy requirements for O2 and H2 production systems, but taking into account their work compression only. This choice permits great freedom in the definition of these thermodynamic cycles and allows general considerations because there is no need of any specification about H2 and/or O2 production systems and their integration with thermodynamic cycles. Therefore this paper can be framed in a context of oxygen and hydrogen centralized production (by nuclear or renewable energy sources for example) and in their distribution as pure gases in the utilization place. Adopting realistic assumptions, TIT of about 1350°C, the potentialities of H2/O2 cycles are very limited: the net efficiency attains a value of about 50%. Instead, adopting futurist assumptions, TIT = I700°C, a different H2/O2 cycle scheme can be proposed and more interesting performance is attained (a net efficiency value over 60%). The thermodynamic and technological aspects are completely addressed in the paper, underlining the great importance of the choice of the main working parameters.

scholarly journals Photocatalytic H2 generation over In2TiO5, Ni substituted In2TiO5 and NiTiO3 – a combined theoretical and experimental study

RSC Advances ◽  
2015 ◽  
Vol 5 (75) ◽  
pp. 61218-61229 ◽  
Author(s):  
A. M. Banerjee ◽  
M. R. Pai ◽  
A. Arya ◽  
S. R. Bharadwaj
Keyword(s):  
Crystal Structure ◽  
Experimental Study ◽  
Optical Absorption ◽  
Electronic Properties ◽  
Absorption Properties ◽  
H2 Generation ◽  
Ni Substitution ◽  
Consequent Effect ◽  
Photocatalytic H2 Generation

Role of Ni substitution in modifying the crystal structure, optical absorption properties and electronic properties of indium titanate, In2(1−x)Ni2xTiO5−δ (0.0 ≤ 2x ≤ 0.4) and its consequent effect on the photocatalytic properties for H2 generation.

scholarly journals Synthesis and Photoactivity of Fe3O4/TiO2-Co as a Magnetically Separable Visible Light Responsive Photocatalyst

2018 ◽  
Vol 18 (3) ◽  
pp. 403 ◽  
Author(s):  
Eko Sri Kunarti ◽  
Indriana Kartini ◽  
Akhmad Syoufian ◽  
Karolina Martha Widyandari
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Dopant Concentration ◽  
Band Gap Energy ◽  
Methylene Blue Solution ◽  
Magnetic Photocatalyst ◽  
Blue Solution ◽  
Degradation Reaction ◽  
Visible Irradiation ◽  
Uv Visible

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.

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