scholarly journals Biogenic Platinum Nanoparticles’ Production by Extremely Acidophilic Fe(III)-Reducing Bacteria

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1175
Author(s):  
Takahiro Matsumoto ◽  
Idol Phann ◽  
Naoko Okibe
Keyword(s):  
Platinum Nanoparticles ◽  
High Performance ◽  
Reduction Reaction ◽  
Vital Role ◽  
Crystal Nucleation ◽  
Acidophilic Bacteria ◽  
Promising Tool ◽  
One Step ◽  
The Difference ◽  
Future Technologies

Platinum nanoparticles (Pt(0)NPs) are expected to play a vital role in future technologies as high-performance catalysts. The microbiological route for Pt(0)NPs’ production is considered a greener and simpler alternative to conventional methods. In order to explore the potential utility of extreme acidophiles, Fe(III)-reducing acidophilic bacteria, Acidocella aromatica and Acidiphilium crytpum, were tested for the production of bio-Pt(0)NPs from an acidic solution. Bio-Pt(0)NPs were successfully formed via a simple one-step reaction with the difference in the size and location between the two strains. Intact enzymatic activity was essential to exhibit the site for Pt(0) crystal nucleation, which enables the formation of well-dispersed, fine bio-Pt(0)NPs. Active Ac. aromatica cells produced the finest bio-Pt(0)NPs of mean and median size of 16.1 and 8.5 nm, respectively. The catalytic activity of bio-Pt(0)NPs was assessed using the Cr(VI) reduction reaction, which was shown to be in a negative linear correlation with the mean particle size under the conditions tested. This is the first study reporting the recruitment of acidophilic extremophiles for the production of Pt(0)NPs. Acidophilic extremophiles often inhabit metal-rich acidic liquors in nature and are expected to become the promising tool for metal nanotechnology.

Intumescent flame retardant-derived P,N co-doped porous carbon as an efficient electrocatalyst for the oxygen reduction reaction

2015 ◽  
Vol 51 (79) ◽  
pp. 14801-14804 ◽  
Author(s):  
Yinling Wang ◽  
Xuemei Zhang ◽  
Anna Li ◽  
Maoguo Li
Keyword(s):  
Oxygen Reduction Reaction ◽  
Flame Retardant ◽  
Oxygen Reduction ◽  
Porous Carbon ◽  
High Performance ◽  
Reduction Reaction ◽  
Intumescent Flame Retardant ◽  
One Step ◽  
Co Doped

Intumescent flame retardant-derived P,N co-doped porous carbon was prepared by one-step pyrolysis, exhibiting high-performance for the oxygen reduction reaction.

One-step scalable preparation of N-doped nanoporous carbon as a high-performance electrocatalyst for the oxygen reduction reaction

Nano Research ◽  
2013 ◽  
Vol 6 (4) ◽  
pp. 293-301 ◽  
Author(s):  
Zhenyu Liu ◽  
Guoxin Zhang ◽  
Zhiyi Lu ◽  
Xiuyan Jin ◽  
Zheng Chang ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Performance ◽  
Nanoporous Carbon ◽  
Reduction Reaction ◽  
One Step

scholarly journals Recent Development of Graphene-Based Cathode Materials for Dye-Sensitized Solar Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-21 ◽  
Author(s):  
Man-Ning Lu ◽  
Chin-Yu Chang ◽  
Tzu-Chien Wei ◽  
Jeng-Yu Lin
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Low Cost ◽  
Inorganic Compounds ◽  
Dye Sensitized Solar Cells ◽  
Reduction Reaction ◽  
Vital Role ◽  
Future Research ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have attracted extensive attention for serving as potential low-cost alternatives to silicon-based solar cells. As a vital role of a typical DSSC, the counter electrode (CE) is generally employed to collect electrons via the external circuit and speed up the reduction reaction ofI3-toI-in the redox electrolyte. The noble Pt is usually deposited on a conductive glass substrate as CE material due to its excellent electrical conductivity, electrocatalytic activity, and electrochemical stability. To achieve cost-efficient DSSCs, reasonable efforts have been made to explore Pt-free alternatives. Recently, the graphene-based CEs have been intensively investigated to replace the high-cost noble Pt CE. In this paper, we provided an overview of studies on the electrochemical and photovoltaic characteristics of graphene-based CEs, including graphene, graphene/Pt, graphene/carbon materials, graphene/conducting polymers, and graphene/inorganic compounds. We also summarize the design and advantages of each graphene-based material and provide the possible directions for designing new graphene-based catalysts in future research for high-performance and low-cost DSSCs.

scholarly journals Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch-Leaf” Electrode for High-Energy Sodium–Sulfur Batteries

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wenyan Du ◽  
Kangqi Shen ◽  
Yuruo Qi ◽  
Wei Gao ◽  
Mengli Tao ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Electrochemical Reaction ◽  
Molecular Layer ◽  
Specific Capacity ◽  
High Energy ◽  
Reduction Reaction ◽  
Biomimetic Design ◽  
Co Nanoparticles ◽  
Sodium Sulfur

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.

scholarly journals N, S and Transition-Metal Co-Doped Graphene Nanocomposites as High-Performance Catalyst for Glucose Oxidation in a Direct Glucose Alkaline Fuel Cell

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 202
Author(s):  
Yexin Dai ◽  
Jie Ding ◽  
Jingyu Li ◽  
Yang Li ◽  
Yanping Zong ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
High Performance ◽  
Glucose Oxidation ◽  
Alkaline Fuel Cell ◽  
Blank Group ◽  
Graphene Nanocomposites ◽  
Doped Graphene ◽  
One Step ◽  
Hydrothermal Approach

In this work, reduced graphene oxide (rGO) nanocomposites doped with nitrogen (N), sulfur (S) and transitional metal (Ni, Co, Fe) were synthesized by using a simple one-step in-situ hydrothermal approach. Electrochemical characterization showed that rGO-NS-Ni was the most prominent catalyst for glucose oxidation. The current density of the direct glucose alkaline fuel cell (DGAFC) with rGO-NS-Ni as the anode catalyst reached 148.0 mA/cm2, which was 40.82% higher than the blank group. The DGAFC exhibited a maximum power density of 48 W/m2, which was more than 2.08 folds than that of blank group. The catalyst was further characterized by SEM, XPS and Raman. It was speculated that the boosted performance was due to the synergistic effect of N, S-doped rGO and the metallic redox couples, (Ni2+/Ni3+, Co2+/Co3+ and Fe2+/Fe3+), which created more active sites and accelerated electron transfer. This research can provide insights for the development of environmental benign catalysts and promote the application of the DGAFCs.

scholarly journals The Mechanical Properties and Damage Evolution of UHPC Reinforced with Glass Fibers and High-Performance Polypropylene Fibers

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Jiayuan He ◽  
Weizhen Chen ◽  
Boshan Zhang ◽  
Jiangjiang Yu ◽  
Hang Liu
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Damage Evolution ◽  
High Performance ◽  
High Performance Concrete ◽  
Glass Fibers ◽  
Ultra High Performance Concrete ◽  
Concrete Damaged Plasticity ◽  
The Difference ◽  
Experimental Values

Due to the sharp and corrosion-prone features of steel fibers, there is a demand for ultra-high-performance concrete (UHPC) reinforced with nonmetallic fibers. In this paper, glass fiber (GF) and the high-performance polypropylene (HPP) fiber were selected to prepare UHPC, and the effects of different fibers on the compressive, tensile and bending properties of UHPC were investigated, experimentally and numerically. Then, the damage evolution of UHPC was further studied numerically, adopting the concrete damaged plasticity (CDP) model. The difference between the simulation values and experimental values was within 5.0%, verifying the reliability of the numerical model. The results indicate that 2.0% fiber content in UHPC provides better mechanical properties. In addition, the glass fiber was more significant in strengthening the effect. Compared with HPP-UHPC, the compressive, tensile and flexural strength of GF-UHPC increased by about 20%, 30% and 40%, respectively. However, the flexural toughness indexes I5, I10 and I20 of HPP-UHPC were about 1.2, 2.0 and 3.8 times those of GF-UHPC, respectively, showing that the toughening effect of the HPP fiber is better.

scholarly journals Facile Synthesis of Uniform Mesoporous Nb2O5 Micro-Flowers for Enhancing Photodegradation of Methyl Orange

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3783
Author(s):  
Jian-Qing Qiu ◽  
Huan-Qing Xie ◽  
Ya-Hao Wang ◽  
Lan Yu ◽  
Fang-Yuan Wang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Active Sites ◽  
High Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Flower Structure ◽  
Electron Microscopies ◽  
Bet Method ◽  
One Step ◽  
Catalytic Active Sites

The removal of organic pollutants using green environmental photocatalytic degradation techniques urgently need high-performance catalysts. In this work, a facile one-step hydrothermal technique has been successfully applied to synthesize a Nb2O5 photocatalyst with uniform micro-flower structure for the degradation of methyl orange (MO) under UV irradiation. These nanocatalysts are characterized by transmission and scanning electron microscopies (TEM and SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, and UV-Vis diffuse reflectance spectroscopy (DRS). It is found that the prepared Nb2O5 micro-flowers presents a good crystal phases and consist of 3D hierarchical nanosheets with 400–500 nm in diameter. The surface area is as large as 48.6 m2 g−1. Importantly, the Nb2O5 micro-flowers exhibit superior catalytic activity up to 99.9% for the photodegradation of MO within 20 mins, which is about 60-fold and 4-fold larger than that of without catalysts (W/O) and commercial TiO2 (P25) sample, respectively. This excellent performance may be attributed to 3D porous structure with abundant catalytic active sites.

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