Role of Acetaldehyde on Synthesizing Large Surface Area Porous g-C3N4 Nanosheets with Enhanced Photocatalytic Performance by Using Acetaldehyde–Melamine

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050066
Author(s):  
Xiangxiang Cheng ◽  
Xiaojuan Xu ◽  
Hongliang Wang ◽  
He Cai ◽  
Lan Jia ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
High Concentration ◽  
Air Atmosphere ◽  
Oxidative Etching

Large specific surface area porous g-C3N4 nanosheets were prepared by utilizing acetaldehyde-mediated melamine. The synthetic processes adopted two-step thermal treatments which are in N2 and then in an air atmosphere. The introduced acetaldehyde made melamine condensation incompletely and generated body defects in g-C3N4 when heated in N2. Further heating in air realized pores formation at sites of body defects, thus increase the specific surface area of g-C3N4. Notably, the introduction of acetaldehyde is beneficial to generate high concentration defects, which are active sites for thermal oxidative etching, and increase the yield of g-C3N4 by inhibiting the sublimation of melamine. The photocatalytic performance of obtained g-C3N4 was evaluated by the degradation of 2-propanol under visible light irradiation ([Formula: see text][Formula: see text]nm). The porous g-C3N4 exhibits excellent photocatalytic performance than bulk g-C3N4. The addition of trace acetaldehyde significantly increased the specific surface area and enhanced photocatalytic activity, providing a new idea for the development of simple, low-cost and high active g-C3N4 photocatalyst.

scholarly journals Continuously Improved Photocatalytic Performance of Zn2SnO4/SnO2/Cu2O Composites by Structural Modulation and Band Alignment Modification

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1390 ◽  
Author(s):  
Tiekun Jia ◽  
Junchao An ◽  
Dongsheng Yu ◽  
Jili Li ◽  
Fang Fu ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Band Alignment ◽  
Energy Utilization ◽  
Structural Modulation ◽  
Hierarchical Architectures

Improving the photocatalytic performance of multi-component photocatalysts through structural modulation and band alignment engineering has attracted great interest in the context of solar energy utilization and conversion. In our work, Zn2SnO4/SnO2 hierarchical architectures comprising nanorod building block assemblies were first achieved via a facile solvothermal synthesis route with lysine and ethylenediamine (EDA) as directing agents, and then chemically etched in NaOH solution to enlarge the surface area and augment active sites. The etched Zn2SnO4/SnO2 hierarchical architectures were further decorated by Cu2O nanoparticles though an in situ chemical deposition method based on band alignment engineering. In comparison with unetched Zn2SnO4/SnO2, the specific surface area of Zn2SnO4/SnO2/Cu2O hierarchical architectures became larger, and the responsive region and absorbance intensity became wider and higher in the whole visible-light range. Zn2SnO4/SnO2/Cu2O hybrid photocatalysts presented enormously improved visible-light photocatalytic behaviour for Rhodamine B (RhB) decomposition. The enhancement of photocatalytic behaviour was dominantly attributed to the synergy effect of the larger specific surface area, higher light absorption capacity, and more effective photo-induced charge carrier separation and migration. A proposed mechanism for the enormously promoted photocatalytic behaviour is brought forth on the basis of the energy-band structure combined with experimental results.

scholarly journals High-Level Oxygen Reduction Catalysts Derived from the Compounds of High-Specific-Surface-Area Pine Peel Activated Carbon and Phthalocyanine Cobalt

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3429
Author(s):  
Lei Zhao ◽  
Ziwei Lan ◽  
Wenhao Mo ◽  
Junyu Su ◽  
Huazhu Liang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
High Performance ◽  
Low Cost ◽  
Specific Area ◽  
High Specific Surface Area ◽  
High Catalytic Activity

Non-platinum carbon-based catalysts have attracted much more attention in recent years because of their low cost and outstanding performance, and are regarded as one of the most promising alternatives to precious metal catalysts. Activated carbon (AC), which has a large specific surface area (SSA), can be used as a carrier or carbon source at the same time. In this work, stable pine peel bio-based materials were used to prepare large-surface-area activated carbon and then compound with cobalt phthalocyanine (CoPc) to obtain a high-performance cobalt/nitrogen/carbon (Co-N-C) catalyst. High catalytic activity is related to increasing the number of Co particles on the large-specific-area activated carbon, which are related with the immersing effect of CoPc into the AC and the rational decomposed temperature of the CoPc ring. The synergy with N promoting the exposure of CoNx active sites is also important. The Eonset of the catalyst treated with a composite proportion of AC and CoPc of 1 to 2 at 800 °C (AC@CoPc-800-1-2) is 1.006 V, higher than the Pt/C (20 wt%) catalyst. Apart from this, compared with other AC/CoPc series catalysts and Pt/C (20 wt%) catalyst, the stability of AC/CoPc-800-1-2 is 87.8% in 0.1 M KOH after 20,000 s testing. Considering the performance and price of the catalyst in a practical application, these composite catalysts combining biomass carbon materials with phthalocyanine series could be widely used in the area of catalysts and energy storage.

scholarly journals Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 149
Author(s):  
André Olean-Oliveira ◽  
Gilberto A. Oliveira Brito ◽  
Celso Xavier Cardoso ◽  
Marcos F. S. Teixeira
Keyword(s):  
Conducting Polymers ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrochemical Sensors ◽  
Structural Characteristics ◽  
Low Cost ◽  
Large Specific Surface Area ◽  
Molecular Architecture ◽  
Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

Elucidating the Origin of the Toxicity of Nano-CeO2 to Chlorella pyrenoidosa：the Role of Specific Surface Area and Chemical Composition

2021 ◽  
Author(s):  
Changjian Xie ◽  
Yuhui Ma ◽  
Peng Zhang ◽  
Junzhe Zhang ◽  
Xiaowei Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aquatic Environment ◽  
Cerium Dioxide ◽  
Environmental Application ◽  
Ecotoxicological Effects

With the increasing environmental application and discharge of nano cerium dioxide (nano-CeO2), it is urgent to fully understand its ecotoxicological effects on the aquatic environment. This study for the first...

Preparation of Fe/N co-doped hierarchical porous carbon nanosheets derived from chitosan nanofibers for high-performance supercapacitors

2021 ◽  
pp. 1-16
Author(s):  
Yaqi Yang ◽  
Ziqiang Shao ◽  
Feijun Wang
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Active Sites ◽  
Transport Pathway ◽  
Carbon Nanosheets ◽  
Hierarchical Porous

Abstract Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.

Three-dimensional graphene encapsulated hollow CoSe2-SnSe2 nanoboxes for high performance asymmetric supercapacitors

2022 ◽  
Author(s):  
Kainan Li ◽  
Ke Zheng ◽  
Zhifang Zhang ◽  
Kuan Li ◽  
Ziyao Bian ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Hollow Structure ◽  
Large Specific Surface Area ◽  
Composite Aerogel

Abstract Construction of metal selenides with a large specific surface area and a hollow structure is one of the effective methods to improve the electrochemical performance of supercapacitors. However, the nano-material easily agglomerates due to the lack of support, resulting in the loss of electrochemical performance. Herein, we successfully design a three-dimensional graphene (3DG) encapsulation-protected hollow nanoboxes (CoSe2-SnSe2) composite aerogel (3DG/CoSe2-SnSe2) via a co-precipitation method coupled with self-assembly route, followed by a high temperature selenidation strategy. The obtained aerogel possesses porous 3DG conductive network, large specific surface area and plenty of reactive active sites. It could be used as a flexible and binder-free electrode after a facile mechanical compression process, which provided a high specific capacitance of 460 F g-1 at 0.5 A g-1, good rate capability of 212.7 F g-1 at 10 A g-1, and excellent cycle stability due to the fast electron/ion transfer and electrolyte diffusion. With the as-prepared 3DG/CoSe2-SnSe2 as positive electrodes and the AC (activated carbon) as negative electrodes, an asymmetric supercapacitor (3DG/CoSe2-SnSe2//AC) was fabricated, which delivered a high specific capacity of 38 F g-1 at 1A g-1 and an energy density of 11.89 W h kg-1 at 749.9 W kg-1, as well as a capacitance retention of 91.1% after 3000 cycles. This work provides a new method for preparing electrode material.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

Titania nanotubes coated with graphene as a promising catalyst for the oxygen reduction reaction

2020 ◽  
Vol 44 (18) ◽  
pp. 7417-7423
Author(s):  
Jiannan Cai ◽  
Xiaofeng Zhang ◽  
Yi Zhang ◽  
Mingxing Yang ◽  
Baohua Huang ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Specific Surface ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Reduction Reaction ◽  
Titania Nanotubes ◽  
Electron Conductivity ◽  
Electrocatalytic Properties

The enhanced electrocatalytic properties of rGO/TiO2NTs for the ORR are a result of increased specific surface area, number of active sites and accelerated electron conductivity.

scholarly journals Synthesis of Au-decorated three-phase-mixed TiO2/phosphate modified active carbon nanocomposites as easily-recycled efficient photocatalysts for degrading high-concentration 2,4-DCP

RSC Advances ◽  
2019 ◽  
Vol 9 (66) ◽  
pp. 38414-38421 ◽  
Author(s):  
Sharafat Ali ◽  
Zhijun Li ◽  
Wajid Ali ◽  
Ziqing Zhang ◽  
Mingzhuo Wei ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Carbon ◽  
Charge Separation ◽  
High Concentration ◽  
Carbon Nanocomposites ◽  
Three Phase

Au decorated three-phase-mixed nanosized TiO2 coupled with phosphate-treated AC as recyclable nanocomposite photocatalysts exhibit excellent photoactivity for degrading high-concentration 2, 4-DCP, mainly due to the improved charge separation and specific surface area.

Sign in / Sign up

Export Citation Format

Share Document