Balancing the piezoelectric coefficient and carrier concentration of materials is key in the field of piezocatalysis.In this work,Bi_(2)WO_(6) material with both piezoelectric and semiconductor properties was chosen a...Balancing the piezoelectric coefficient and carrier concentration of materials is key in the field of piezocatalysis.In this work,Bi_(2)WO_(6) material with both piezoelectric and semiconductor properties was chosen as a model material.A one-step ethylene glycol(EG)-assisted solvothermal method was used to synthesize Bi2WO6 with oxygen vacancies.By controlling the solvothermal time and temperature,the oxygen vacancy concentration(COV)was regulated.As COV increases,the piezoelectric coefficient decreases,the carrier concentration increases,and the hydrogen production rate first increases but then decreases.When COV reaches 1.45×10^(12) spins·mg^(−1),the corresponding piezoelectric coefficient and carrier concentration are 13.9 pm·V^(−1) and 2.90×10^(20) cm^(−3),respectively.The optimal hydrogen production rate per power of 2.21μmol·g^(−1)·h^(−1)·W^(−1) is equivalent to or even better than that of most reported piezocatalysts.The piezoelectric coefficient and carrier concentration,as two factors,jointly determine the piezocatalytic performance.The findings of this research can provide important and deep-seated insights for better piezocatalysts in the future.展开更多
In this work, oxygen vacancy-regulated La_(0.7)Ca_(0.3)MnO_(3-δ):Ag (LCMO:A) nanocomposite thin films onLaAlO_(3) (001) substrates were investigated to obtain films with large temperature coefficient of resistance(TC...In this work, oxygen vacancy-regulated La_(0.7)Ca_(0.3)MnO_(3-δ):Ag (LCMO:A) nanocomposite thin films onLaAlO_(3) (001) substrates were investigated to obtain films with large temperature coefficient of resistance(TCR) values. LCMO:A nanocomposite thin films were synthesized using pulsed laser deposition, andoxygen pressures during film deposition and annealing steps were optimized. As oxygen pressuresincreased, lattice parameter increased from 70 Pa to 100 Pa, Tp increased monotonically from 168 K to282 K, and average Mn^(4+) concentration in the film increased as indicated by X-ray photoemissionspectroscopy data. Record high TCR value of ~37% K^(-1) was achieved in LCMO:A nanocomposite thin filmprepared with optimal oxygen pressures, making this film promising candidate for applications inbolometers.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22309170,51972294,and 51972291)the Natural Science Foundation of Zhejiang Province(No.LQ24E020003)the Open Fund Project of the National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization of Nanchang Hangkong University(No.ES202480182).
文摘Balancing the piezoelectric coefficient and carrier concentration of materials is key in the field of piezocatalysis.In this work,Bi_(2)WO_(6) material with both piezoelectric and semiconductor properties was chosen as a model material.A one-step ethylene glycol(EG)-assisted solvothermal method was used to synthesize Bi2WO6 with oxygen vacancies.By controlling the solvothermal time and temperature,the oxygen vacancy concentration(COV)was regulated.As COV increases,the piezoelectric coefficient decreases,the carrier concentration increases,and the hydrogen production rate first increases but then decreases.When COV reaches 1.45×10^(12) spins·mg^(−1),the corresponding piezoelectric coefficient and carrier concentration are 13.9 pm·V^(−1) and 2.90×10^(20) cm^(−3),respectively.The optimal hydrogen production rate per power of 2.21μmol·g^(−1)·h^(−1)·W^(−1) is equivalent to or even better than that of most reported piezocatalysts.The piezoelectric coefficient and carrier concentration,as two factors,jointly determine the piezocatalytic performance.The findings of this research can provide important and deep-seated insights for better piezocatalysts in the future.
基金The work is supported by Key Area Research Plan of Guangdong(No.2020B010176001)Shenzhen Science and Technology Program(Nos.KQTD20180411143514543 and JCYJ20180504165831308)Shenzhen DRC project[2018]1433.
文摘In this work, oxygen vacancy-regulated La_(0.7)Ca_(0.3)MnO_(3-δ):Ag (LCMO:A) nanocomposite thin films onLaAlO_(3) (001) substrates were investigated to obtain films with large temperature coefficient of resistance(TCR) values. LCMO:A nanocomposite thin films were synthesized using pulsed laser deposition, andoxygen pressures during film deposition and annealing steps were optimized. As oxygen pressuresincreased, lattice parameter increased from 70 Pa to 100 Pa, Tp increased monotonically from 168 K to282 K, and average Mn^(4+) concentration in the film increased as indicated by X-ray photoemissionspectroscopy data. Record high TCR value of ~37% K^(-1) was achieved in LCMO:A nanocomposite thin filmprepared with optimal oxygen pressures, making this film promising candidate for applications inbolometers.
