Photogenerated-hole scavenger for enhancing photocatalytic chalcopyrite bioleaching

2020 ◽  
Vol 30 (1) ◽  
pp. 200-211 ◽  
Author(s):  
Bao-jun YANG ◽  
Wen LUO ◽  
Qi LIAO ◽  
Jian-yu ZHU ◽  
Min GAN ◽  
...  
Nanoscale ◽  
2021 ◽  
Author(s):  
Chun-Yan Shih ◽  
Wei-Lun Huang ◽  
I-Ting Chiang ◽  
Wu-Chou Su ◽  
Hsisheng Teng

Tuning of the nitrogen-doped graphene oxide dot and ascorbic acid concentrations can selectively kill cancer cells through either apoptosis or necrosis.


2017 ◽  
Vol 9 (39) ◽  
pp. 33887-33895 ◽  
Author(s):  
Heng Zhu ◽  
Shicheng Yan ◽  
Zhaosheng Li ◽  
Zhigang Zou

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 430 ◽  
Author(s):  
Elnaz Bahadori ◽  
Antonio Tripodi ◽  
Alberto Villa ◽  
Carlo Pirola ◽  
Laura Prati ◽  
...  

The photoreduction of CO2 is an intriguing process which allows the synthesis of fuels and chemicals. One of the limitations for CO2 photoreduction in the liquid phase is its low solubility in water. This point has been here addressed by designing a fully innovative pressurized photoreactor, allowing operation up to 20 bar and applied to improve the productivity of this very challenging process. The photoreduction of CO2 in the liquid phase was performed using commercial TiO2 (Evonink P25), TiO2 obtained by flame spray pyrolysis (FSP) and gold doped P25 (0.2 wt% Au-P25) in the presence of Na2SO3 as hole scavenger (HS). The different reaction parameters (catalyst concentration, pH and amount of HS) have been addressed. The products in liquid phase were mainly formic acid and formaldehyde. Moreover, for longer reaction time and with total consumption of HS, gas phase products formed (H2 and CO) after accumulation of significant number of organic compounds in the liquid phase, due to their consecutive photoreforming. Enhanced CO2 solubility in water was achieved by adding a base (pH = 12–14). In basic environment, CO2 formed carbonates which further reduced to formaldehyde and formic acid and consequently formed CO/CO2 + H2 in the gas phase through photoreforming. The deposition of small Au nanoparticles (3–5 nm) (NPs) onto TiO2 was found to quantitatively influence the products distribution and increase the selectivity towards gas phase products. Significant energy storage in form of different products has been achieved with respect to literature results.


ChemPhysChem ◽  
2016 ◽  
Vol 17 (24) ◽  
pp. 4102-4109 ◽  
Author(s):  
Tao Ye ◽  
Xi Jiang ◽  
Dongyang Wan ◽  
Xingzhi Wang ◽  
Jun Xing ◽  
...  

Molekul ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. 6
Author(s):  
Kapti Riyani ◽  
Tien Setyaningtyas

TiO2­ photocatalyst can be used to reduce heavy metal ions into common metal ion or metal ion with lower coordination number. This research aimed to (1) study the influence of pH on the photoreduction activity of Pb2+ion by TiO2­, (2) study the influence of hole scavenger on the photoreduction activity of Pb2+ ion by TiO2­, (3) study the influence of light source on the photoreduction activity of Pb2+ ion by TiO2­. The method used on this research is laboratory experiment consist of the making of TiO2 thin film, standard Pb2+ photoreduction with the variation of pH, standard Pb2+ photoreduction with the variation of light source. The results of Pb2+ photoreduction are analyzed by Atomic Absorption Spectroscopy. The result of the research showed that the activity of TiO2 to reduce Pb2+ can be optimum at pH 6, oxalic acid as hole scavenger and UV lamp use. The sunlight can also be used as the light source to reduce Pb2+ by TiO2 photocatalyst.


ChemCatChem ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 5875-5884 ◽  
Author(s):  
Rui Sun ◽  
Ziqing Zhang ◽  
Zhijun Li ◽  
Liqiang Jing

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 72 ◽  
Author(s):  
Yin-Hsuan Chang ◽  
Ming-Chung Wu

Heavy metal pollution of wastewater with coexisting organic contaminants has become a serious threat to human survival and development. In particular, hexavalent chromium, which is released into industrial wastewater, is both toxic and carcinogenic. TiO2 photocatalysts have attracted much attention due to their potential photodegradation and photoreduction abilities. Though TiO2 demonstrates high photocatalytic performance, it is a difficult material to recycle after the photocatalytic reaction. Considering the secondary pollution caused by the photocatalysts, in this study we prepared Ag/Fe3O4/TiO2 nanofibers (NFs) that could be magnetically separated using hydrothermal synthesis, which was considered a benign and effective resolution. For the photocatalytic test, the removal of Cr(VI) was carried out by Ag/Fe3O4/TiO2 nanofibers combined with ammonium oxalate (AO). AO acted as a hole scavenger to enhance the electron-hole separation ability, thereby dramatically enhancing the photoreduction efficiency of Cr(VI). The reaction rate constant for Ag/Fe3O4/TiO2 NFs in the binary system reached 0.260 min−1, 6.95 times of that of Ag/Fe3O4/TiO2 NFs in a single system (0.038 min−1). The optimized Ag/Fe3O4/TiO2 NFs exhibited high efficiency and maintained their photoreduction efficiency at 90% with a recyclability of 87% after five cycles. Hence, taking into account the high magnetic separation behavior, Ag/Fe3O4/TiO2 NFs with a high recycling capability are a potential photocatalyst for wastewater treatment.


Author(s):  
Bahngmi Jung ◽  
Fatima Abu-Rub ◽  
Abdellatif El-Ghenymy ◽  
Wei Deng ◽  
Ying Li ◽  
...  

2006 ◽  
Vol 128 (7) ◽  
pp. 2212-2213 ◽  
Author(s):  
Ryuhei Yamagami ◽  
Kazuo Kobayashi ◽  
Akinori Saeki ◽  
Shu Seki ◽  
Seiichi Tagawa

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