WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag...WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag_2O/WO_3复合光催化剂。选择亚甲基蓝为研究对象,测定了不同摩尔比的Ag_2O/WO_3复合催化剂的光催化性能。实验表明,当Ag_2O和WO_3的摩尔配比为1∶2时,该复合催化剂的光催性能最好。过量的Ag_2O纳米颗粒会增加Ag_2O/WO_3内部电子空穴的复合几率,反而导致光催化剂反应活性的降低。展开更多
用传统的固相无压烧结法制备了Li_(0.02)(Na_(0.52)K_(0.48))_(0.98)Nb_(0.8)Ta_(0.2O3)-x Ag_2O(0≤x≤0.1)无铅压电陶瓷,研究了Ag_2O掺杂对陶瓷电性能的影响。研究发现,适当掺杂Ag_2O能显著提高陶瓷的电性能,在1090℃的烧结温度下,当...用传统的固相无压烧结法制备了Li_(0.02)(Na_(0.52)K_(0.48))_(0.98)Nb_(0.8)Ta_(0.2O3)-x Ag_2O(0≤x≤0.1)无铅压电陶瓷,研究了Ag_2O掺杂对陶瓷电性能的影响。研究发现,适当掺杂Ag_2O能显著提高陶瓷的电性能,在1090℃的烧结温度下,当掺杂量为0.06时,陶瓷的压电性能最佳,d33、Кp、εr、Pr均达到最大(d33=229 p C/N,Кp=55.2%,εr=802,Pr=23μC/cm^2),矫顽场降到最低(Ec=12 k V/cm),应变达到2.0%。但Ag_2O的添加使陶瓷的机械品质因数Qm由139.7降到了58.8,使介电损耗tanδ由1.38%增加到了2.7%。展开更多
In this study,Ag/γ-Al_(2)O_(3)catalysts were synthesized by an Ar dielectric barrier discharge plasma using silver nitrate as the Ag source andγ-alumina(γ-Al_(2)O_(3))as the support.It is revealed that plasma can r...In this study,Ag/γ-Al_(2)O_(3)catalysts were synthesized by an Ar dielectric barrier discharge plasma using silver nitrate as the Ag source andγ-alumina(γ-Al_(2)O_(3))as the support.It is revealed that plasma can reduce silver ions to generate crystalline silver nanoparticles(Ag NPs)of good dispersion and uniformity on the alumina surface,leading to the formation of Ag/γ-Al_(2)O_(3)catalysts in a green manner without traditional chemical reductants.Ag/γ-Al_(2)O_(3)exhibited good catalytic activity and stability in CO oxidation reactions,and the activity increased with increase in the Ag content.For catalysts with more than 2 wt%Ag,100%CO conversion can be achieved at 300°C.The catalytic activity of the Ag/γ-Al_(2)O_(3)catalysts is also closely related to the size of theγ-alumina,where Ag/nano-γ-Al_(2)O_(3)catalysts demonstrate better performance than Ag/micro-γ-Al_(2)O_(3)catalysts with the same Ag content.In addition,the catalytic properties of plasma-generated Ag/nano-γ-Al_(2)O_(3)(Ag/γ-Al_(2)O_(3)-P)catalysts were compared with those of Ag/nano-γ-Al_(2)O_(3)catalysts prepared by the traditional calcination approach(Ag/γ-Al_(2)O_(3)-C),with the plasma-generated samples demonstrating better overall performance.This simple,rapid and green plasma process is considered to be applicable for the synthesis of diverse noble metal-based catalysts.展开更多
文摘WO_3是一种带隙约为2.7 e V的过渡金属半导体,可见光就能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO_3纳米材料催化活性偏低,针对这一难题,本文选取了三维网格结构的WO_3纳米材料为载体,利用化学搅拌法制备了不同摩尔比的Ag_2O/WO_3复合光催化剂。选择亚甲基蓝为研究对象,测定了不同摩尔比的Ag_2O/WO_3复合催化剂的光催化性能。实验表明,当Ag_2O和WO_3的摩尔配比为1∶2时,该复合催化剂的光催性能最好。过量的Ag_2O纳米颗粒会增加Ag_2O/WO_3内部电子空穴的复合几率,反而导致光催化剂反应活性的降低。
文摘用传统的固相无压烧结法制备了Li_(0.02)(Na_(0.52)K_(0.48))_(0.98)Nb_(0.8)Ta_(0.2O3)-x Ag_2O(0≤x≤0.1)无铅压电陶瓷,研究了Ag_2O掺杂对陶瓷电性能的影响。研究发现,适当掺杂Ag_2O能显著提高陶瓷的电性能,在1090℃的烧结温度下,当掺杂量为0.06时,陶瓷的压电性能最佳,d33、Кp、εr、Pr均达到最大(d33=229 p C/N,Кp=55.2%,εr=802,Pr=23μC/cm^2),矫顽场降到最低(Ec=12 k V/cm),应变达到2.0%。但Ag_2O的添加使陶瓷的机械品质因数Qm由139.7降到了58.8,使介电损耗tanδ由1.38%增加到了2.7%。
基金financial support from National Natural Science Foundation of China(Nos.52004102 and 22078125)Postdoctoral Science Foundation of China(No.2021M690068)+2 种基金Fundamental Research Funds for the Central Universities(Nos.JUSRP221018 and JUSRP622038)Key Laboratory of Green Cleaning Technology and Detergent of Zhejiang Province(No.Q202204)Open Project of Key Laboratory of Green Chemical Engineering Process of Ministry of Education(No.GCP202112)。
文摘In this study,Ag/γ-Al_(2)O_(3)catalysts were synthesized by an Ar dielectric barrier discharge plasma using silver nitrate as the Ag source andγ-alumina(γ-Al_(2)O_(3))as the support.It is revealed that plasma can reduce silver ions to generate crystalline silver nanoparticles(Ag NPs)of good dispersion and uniformity on the alumina surface,leading to the formation of Ag/γ-Al_(2)O_(3)catalysts in a green manner without traditional chemical reductants.Ag/γ-Al_(2)O_(3)exhibited good catalytic activity and stability in CO oxidation reactions,and the activity increased with increase in the Ag content.For catalysts with more than 2 wt%Ag,100%CO conversion can be achieved at 300°C.The catalytic activity of the Ag/γ-Al_(2)O_(3)catalysts is also closely related to the size of theγ-alumina,where Ag/nano-γ-Al_(2)O_(3)catalysts demonstrate better performance than Ag/micro-γ-Al_(2)O_(3)catalysts with the same Ag content.In addition,the catalytic properties of plasma-generated Ag/nano-γ-Al_(2)O_(3)(Ag/γ-Al_(2)O_(3)-P)catalysts were compared with those of Ag/nano-γ-Al_(2)O_(3)catalysts prepared by the traditional calcination approach(Ag/γ-Al_(2)O_(3)-C),with the plasma-generated samples demonstrating better overall performance.This simple,rapid and green plasma process is considered to be applicable for the synthesis of diverse noble metal-based catalysts.
基金supported by the National Natural Science Foundation of China(51572103 and 51502106)the Distinguished Young Scholar of Anhui Province(1808085J14)+2 种基金the Foundation for Young Talents in College of Anhui Province(gxyqZD2017051)the Key Foundation of Educational Commission of Anhui Province(KJ2016SD53)the Innovation Team of Design and Application of Advanced Energetic Materials(KJ2015TD003)~~
基金supported by the Natural Science Foundation of Hebei Province,China(B2014209182)Youth Foundation of Hebei Education Department,China(QN2014045)College Students'Innovative Entrepreneurial Training Plan Program of North China University of Science and Technology,China(X2015117)~~
文摘水热法结合原位沉淀法成功制备新型磁性溴化银/磷酸银/铁酸锌(AgBr/Ag_3PO_4/ZnFe_2O_4)复合催化剂,并通过X射线衍射、能量色散X射线、场发射扫描电子显微镜、透射电子显微镜和紫外-可见漫反射光谱对其晶相结构、组成、形貌及吸光性能进行了表征。在可见光照射下,所制备的AgBr/Ag_3PO_4/ZnFe_2O_4复合催化剂光催化降解罗丹明B(RhB)的活性优于Ag_3PO_4/ZnFe_2O_4、AgBr/ZnFe_2O_4和P25 TiO_2。在酸性和碱性溶液中,AgBr/Ag_3PO_4/ZnFe_2O_4光催化剂呈现出优良光催化性能。在AgBr/Ag_3PO_4/ZnFe_2O_4体系中,光催化降解Rh B的速率随着反应体系温度的升高而增大,由阿伦尼乌斯方程计算获得反应体系活化能为31.9 k J?mol^(-1)。AgBr/Ag_3PO_4/ZnFe_2O_4复合材料优异的可见光催化活性归因于光生电荷的有效分离,所产生的超氧自由基和空穴是Rh B降解的主要活性物种。
