Polymerization of 2-(4-halophenyl)-1,3-butadiene(2-XPB) and their copolymerization with isoprene using a yttrium catalyst have been examined. The β-diketiminato yttrium bis(alkyl) complex(1) activated by [Ph_3 C][B(C...Polymerization of 2-(4-halophenyl)-1,3-butadiene(2-XPB) and their copolymerization with isoprene using a yttrium catalyst have been examined. The β-diketiminato yttrium bis(alkyl) complex(1) activated by [Ph_3 C][B(C_(6) F_(5))_(4)] and Ali Bu3 shows high cis-1,4-selectivity(>98%) for the polymerization of 2-XPB(2-XPB = 2-FPB, 2-Cl PB and 2-Br PB) to afford halogenated plastic poly(dienes) with glass transition temperatures of30–55 ℃. Moreover, the copolymerization of 2-XPB with isoprene(IP) has also been achieved by this catalyst, and the insertion ratios of 2-XPB can be facilely tuned in a full range of 0%–100% simply by changing the 2-XPB-to-IP ratio. Quantitative hydrogenation of cis-1,4-poly(2-XPB) results in perfect alternating ethylene-halostyrene copolymers, and an alternating copolymer of 4-vinylbenzoic acid with ethylene is obtained by a consecutive reaction of ethylene-4-bromostyrene copolymer with ^(n)Bu Li, CO_(2) and HCl.展开更多
CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport e...CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport efficiency of photogenerated carriers.To address the above issues,a cost-effective ternary Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode was designed.Firstly,a thin Cu:NiO_(X)film was inserted between CuBi_(2)O_(4)and FTO conducting substrate as a hole-selective layer,which promotes the transmission of photogenerated holes to the FTO substrate effectively.Furthermore,the modification of CuO film on the CuBi_(2)O_(4)electrode not only increases the absorption of sunlight and generates more photogenerated carriers,but also constitutes a heterojunction with CuBi_(2)O_(4),creating a built-in electric field,which facilitates the separation of electrons and holes,and accelerates the electrons transfer to electrode–electrolyte interface.The fabricated Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode exhibits a surprisingly high photocurrent density of−1.51 mA·cm^(−2)at 0.4 V versus RHE,which is 2.6 times that of the pristine CuBi_(2)O_(4)photocathode.The improved PEC performance is attributed to the synergy effect of the Cu:NiO_(X)hole-selective layer and the CuBi_(2)O_(4)/CuO heterojunction.Moreover,the combination with the BiVO_(4)/CoS,an unbiased overall water splitting was achieved,which has a photocurrent of 0.193 mA·cm^(−2).展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 21634007 and 51773193)the Department of Science and Technology of Jilin Province(No. 20180101171JC)。
文摘Polymerization of 2-(4-halophenyl)-1,3-butadiene(2-XPB) and their copolymerization with isoprene using a yttrium catalyst have been examined. The β-diketiminato yttrium bis(alkyl) complex(1) activated by [Ph_3 C][B(C_(6) F_(5))_(4)] and Ali Bu3 shows high cis-1,4-selectivity(>98%) for the polymerization of 2-XPB(2-XPB = 2-FPB, 2-Cl PB and 2-Br PB) to afford halogenated plastic poly(dienes) with glass transition temperatures of30–55 ℃. Moreover, the copolymerization of 2-XPB with isoprene(IP) has also been achieved by this catalyst, and the insertion ratios of 2-XPB can be facilely tuned in a full range of 0%–100% simply by changing the 2-XPB-to-IP ratio. Quantitative hydrogenation of cis-1,4-poly(2-XPB) results in perfect alternating ethylene-halostyrene copolymers, and an alternating copolymer of 4-vinylbenzoic acid with ethylene is obtained by a consecutive reaction of ethylene-4-bromostyrene copolymer with ^(n)Bu Li, CO_(2) and HCl.
基金supported by the National Natural Science Foundation of China(No.61804039)the University Natural Sciences Research Project of Anhui Province(No.2022AH010096)+1 种基金the Talent Research Fund of Hefei University(No.20RC35)the Natural Science Foundation of Anhui Higher Education Institution of China(No.2023AH040160).
文摘CuBi_(2)O_(4)is identified as a promising photocathode in photoelectrochemical(PEC)water splitting systems.However,the PEC performance of CuBi_(2)O_(4)is far from expected due to the limited separation and transport efficiency of photogenerated carriers.To address the above issues,a cost-effective ternary Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode was designed.Firstly,a thin Cu:NiO_(X)film was inserted between CuBi_(2)O_(4)and FTO conducting substrate as a hole-selective layer,which promotes the transmission of photogenerated holes to the FTO substrate effectively.Furthermore,the modification of CuO film on the CuBi_(2)O_(4)electrode not only increases the absorption of sunlight and generates more photogenerated carriers,but also constitutes a heterojunction with CuBi_(2)O_(4),creating a built-in electric field,which facilitates the separation of electrons and holes,and accelerates the electrons transfer to electrode–electrolyte interface.The fabricated Cu:NiO_(X)/CuBi_(2)O_(4)/CuO composite photocathode exhibits a surprisingly high photocurrent density of−1.51 mA·cm^(−2)at 0.4 V versus RHE,which is 2.6 times that of the pristine CuBi_(2)O_(4)photocathode.The improved PEC performance is attributed to the synergy effect of the Cu:NiO_(X)hole-selective layer and the CuBi_(2)O_(4)/CuO heterojunction.Moreover,the combination with the BiVO_(4)/CoS,an unbiased overall water splitting was achieved,which has a photocurrent of 0.193 mA·cm^(−2).
