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Enhanced NH3-Sensitivity of Reduced Graphene Oxide Modified by Tetra-α-Iso-Pentyloxymetallophthalocyanine Derivatives.

Li X, Wang B, Wang X, Zhou X, Chen Z, He C, Yu Z, Wu Y - Nanoscale Res Lett (2015)

Bottom Line: Three kinds of novel hybrid materials were prepared by noncovalent functionalized reduced graphene oxide (rGO) with tetra-α-iso-pentyloxyphthalocyanine copper (CuPc), tetra-α-iso-pentyloxyphthalocyanine nickel (NiPc) and tetra-α-iso-pentyloxyphthalocyanine lead (PbPc) and characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), Raman spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and atomic force microscope (AFM).The as-synthesized MPc/rGO hybrids show excellent NH3 gas-sensing performance with high response value and fast recovery time compared with bare rGO.The enhancement of the sensing response is mainly attributed to the synergism of gas adsorption of MPc to NH3 gas and conducting network of rGO with greater electron transfer efficiency.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China. wangbin@hlju.edu.cn.

ABSTRACT
Three kinds of novel hybrid materials were prepared by noncovalent functionalized reduced graphene oxide (rGO) with tetra-α-iso-pentyloxyphthalocyanine copper (CuPc), tetra-α-iso-pentyloxyphthalocyanine nickel (NiPc) and tetra-α-iso-pentyloxyphthalocyanine lead (PbPc) and characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), Raman spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and atomic force microscope (AFM). The as-synthesized MPc/rGO hybrids show excellent NH3 gas-sensing performance with high response value and fast recovery time compared with bare rGO. The enhancement of the sensing response is mainly attributed to the synergism of gas adsorption of MPc to NH3 gas and conducting network of rGO with greater electron transfer efficiency. Strategies for combining the good properties of rGO and MPc derivatives will open new opportunities for preparing and designing highly efficient rGO chemiresistive gas-sensing hybrid materials for potential applications in gas sensor field.

No MeSH data available.


Related in: MedlinePlus

a Response times, b recovery times, c response of rGO and MPc/rGO hybrid sensors versus NH3 concentrations at room temperature, d response of rGO and MPc/rGO hybrid sensors to 50 ppm NH3, CO2, H2, CH4, and CO gas
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Fig8: a Response times, b recovery times, c response of rGO and MPc/rGO hybrid sensors versus NH3 concentrations at room temperature, d response of rGO and MPc/rGO hybrid sensors to 50 ppm NH3, CO2, H2, CH4, and CO gas

Mentions: The resistance trace of sensors was measured with the voltage fixed at 3 V between the interdigitated electrodes. An ohmic response was generated with the MPc/rGO hybrids for NH3 gas concentrations of 0.4–3200 ppm, as shown in Fig. 7d–f. The results show that the resistance of the sensors increases dramatically with the increase of NH3 gases concentration, indicating the p-type response of MPc/rGO hybrids. The MPc/rGO hybrid sensors recover to the original resistance value in the absence of NH3 gases. Figure 8a, b shows response and recovery time of MPc/rGO hybrid sensors to different concentration of NH3 gas. For example, the response times of CuPc/rGO, NiPc/rGO, and PbPc/rGO sensors to 800 ppb NH3 are 364, 200, 248 s, and the recovery times of CuPc/rGO, NiPc/rGO, and PbPc/rGO sensors to 800 ppb NH3 are 115, 264, 331 s, respectively. Generally speaking, the recovery time of MPc/rGO hybrid sensors increases with raised concentration of NH3. It is possible that the NH3 molecules interact firstly with MPc blending rGO surface, then the NH3 molecules move then into the external and inside of rGO, which is more slow recovery process. The bigger the gas concentration, the greater interaction between rGO and NH3 gas, the sensors need longer recovery time. But the MPc/rGO hybrid sensors can recover completely to the original value within 830 s, even when the concentration of 3200 ppm is used. As for pure rGO, the resistance of rGO sensor can not recover to the original resistance in an hour with the increase of the NH3 gas concentration [20], indicating the improved recovery performance of rGO after their functional modification with MPc. Moreover, the response and recovery time order of MPc/rGO hybrids to NH3 coincides with our previous studies of the gas-sensing properties of the individual MPc molecules [18], which indicates that the attachment of MPc plays an important role in gas-sensing performance of MPc/rGO hybrids. The differences of the three kinds of sensors are generally related with the structure of MPc. The order of the radius of metal ions is Cu2+ (73 pm) ≈ Ni2+ (72 pm) < Pb2+ (120 pm), and the number of the d-electron is Pb 2+ (10) < Ni2+ (8) = Cu2+. The smaller the ions radius, the fewer the d-electron, the weaker the d-electron contribution of the central metal to the π-electron in conjugated ring, so the acceptor power of phthalocyanine macrocycle is increased, NH3 is an electron-donating (reducing) gas, thus strengthening the adsorption with facile production of ionized states and hole traps which are formed from strong interactions from NH3 to phthalocyanine macrocycles. Therefore, the recovery time of MPc/rGO hybrids vary between 115 and 331 s.Fig. 8


Enhanced NH3-Sensitivity of Reduced Graphene Oxide Modified by Tetra-α-Iso-Pentyloxymetallophthalocyanine Derivatives.

Li X, Wang B, Wang X, Zhou X, Chen Z, He C, Yu Z, Wu Y - Nanoscale Res Lett (2015)

a Response times, b recovery times, c response of rGO and MPc/rGO hybrid sensors versus NH3 concentrations at room temperature, d response of rGO and MPc/rGO hybrid sensors to 50 ppm NH3, CO2, H2, CH4, and CO gas
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Fig8: a Response times, b recovery times, c response of rGO and MPc/rGO hybrid sensors versus NH3 concentrations at room temperature, d response of rGO and MPc/rGO hybrid sensors to 50 ppm NH3, CO2, H2, CH4, and CO gas
Mentions: The resistance trace of sensors was measured with the voltage fixed at 3 V between the interdigitated electrodes. An ohmic response was generated with the MPc/rGO hybrids for NH3 gas concentrations of 0.4–3200 ppm, as shown in Fig. 7d–f. The results show that the resistance of the sensors increases dramatically with the increase of NH3 gases concentration, indicating the p-type response of MPc/rGO hybrids. The MPc/rGO hybrid sensors recover to the original resistance value in the absence of NH3 gases. Figure 8a, b shows response and recovery time of MPc/rGO hybrid sensors to different concentration of NH3 gas. For example, the response times of CuPc/rGO, NiPc/rGO, and PbPc/rGO sensors to 800 ppb NH3 are 364, 200, 248 s, and the recovery times of CuPc/rGO, NiPc/rGO, and PbPc/rGO sensors to 800 ppb NH3 are 115, 264, 331 s, respectively. Generally speaking, the recovery time of MPc/rGO hybrid sensors increases with raised concentration of NH3. It is possible that the NH3 molecules interact firstly with MPc blending rGO surface, then the NH3 molecules move then into the external and inside of rGO, which is more slow recovery process. The bigger the gas concentration, the greater interaction between rGO and NH3 gas, the sensors need longer recovery time. But the MPc/rGO hybrid sensors can recover completely to the original value within 830 s, even when the concentration of 3200 ppm is used. As for pure rGO, the resistance of rGO sensor can not recover to the original resistance in an hour with the increase of the NH3 gas concentration [20], indicating the improved recovery performance of rGO after their functional modification with MPc. Moreover, the response and recovery time order of MPc/rGO hybrids to NH3 coincides with our previous studies of the gas-sensing properties of the individual MPc molecules [18], which indicates that the attachment of MPc plays an important role in gas-sensing performance of MPc/rGO hybrids. The differences of the three kinds of sensors are generally related with the structure of MPc. The order of the radius of metal ions is Cu2+ (73 pm) ≈ Ni2+ (72 pm) < Pb2+ (120 pm), and the number of the d-electron is Pb 2+ (10) < Ni2+ (8) = Cu2+. The smaller the ions radius, the fewer the d-electron, the weaker the d-electron contribution of the central metal to the π-electron in conjugated ring, so the acceptor power of phthalocyanine macrocycle is increased, NH3 is an electron-donating (reducing) gas, thus strengthening the adsorption with facile production of ionized states and hole traps which are formed from strong interactions from NH3 to phthalocyanine macrocycles. Therefore, the recovery time of MPc/rGO hybrids vary between 115 and 331 s.Fig. 8

Bottom Line: Three kinds of novel hybrid materials were prepared by noncovalent functionalized reduced graphene oxide (rGO) with tetra-α-iso-pentyloxyphthalocyanine copper (CuPc), tetra-α-iso-pentyloxyphthalocyanine nickel (NiPc) and tetra-α-iso-pentyloxyphthalocyanine lead (PbPc) and characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), Raman spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and atomic force microscope (AFM).The as-synthesized MPc/rGO hybrids show excellent NH3 gas-sensing performance with high response value and fast recovery time compared with bare rGO.The enhancement of the sensing response is mainly attributed to the synergism of gas adsorption of MPc to NH3 gas and conducting network of rGO with greater electron transfer efficiency.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China. wangbin@hlju.edu.cn.

ABSTRACT
Three kinds of novel hybrid materials were prepared by noncovalent functionalized reduced graphene oxide (rGO) with tetra-α-iso-pentyloxyphthalocyanine copper (CuPc), tetra-α-iso-pentyloxyphthalocyanine nickel (NiPc) and tetra-α-iso-pentyloxyphthalocyanine lead (PbPc) and characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), Raman spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and atomic force microscope (AFM). The as-synthesized MPc/rGO hybrids show excellent NH3 gas-sensing performance with high response value and fast recovery time compared with bare rGO. The enhancement of the sensing response is mainly attributed to the synergism of gas adsorption of MPc to NH3 gas and conducting network of rGO with greater electron transfer efficiency. Strategies for combining the good properties of rGO and MPc derivatives will open new opportunities for preparing and designing highly efficient rGO chemiresistive gas-sensing hybrid materials for potential applications in gas sensor field.

No MeSH data available.


Related in: MedlinePlus