Jingzhe Li | Lam Research (original) (raw)
Papers by Jingzhe Li
Microchimica Acta, 2022
Current solid-contact ion-selective electrodes (ISEs) suffer from signal-to-noise drift and short... more Current solid-contact ion-selective electrodes (ISEs) suffer from signal-to-noise drift and short lifespans partly due to water uptake and the development of an aqueous layer between the transducer and ion-selective membrane. To address these challenges, we report on a nitrate ISE based on hydrophobic laser-induced graphene (LIG) coated with a poly(vinyl) chloride–based nitrate selective membrane. The hydrophobic LIG was created using a polyimide substrate and a double lasing process under ambient conditions (air at 23.0 ± 1.0 °C) that resulted in a static water contact angle of 135.5 ± 0.7° (mean ± standard deviation) in wettability testing. The LIG–ISE displayed a Nernstian response of − 58.17 ± 4.21 mV dec−1 and a limit-of-detection (LOD) of 6.01 ± 1.44 µM. Constant current chronopotentiometry and a water layer test were used to evaluate the potential (emf) signal stability with similar performance to previously published work with graphene-based ISEs. Using a portable potentiostat, the sensor displayed comparable (p > 0.05) results to a US Environmental Protection Agency (EPA)–accepted analytical method when analyzing water samples collected from two lakes in Ames, IA. The sensors were stored in surface water samples for 5 weeks and displayed nonsignificant difference in performance (LOD and sensitivity). These results, combined with a rapid and low-cost fabrication technique, make the development of hydrophobic LIG–ISEs appealing for a wide range of long-term in situ surface water quality applications.
The integration of microfluidics and electrochemical cells is at the forefront of emerging sensor... more The integration of microfluidics and electrochemical cells is at the forefront of emerging sensors and energy systems; however, a fabrication scheme that can create both the microfluidics and electrochemical cells in a scalable fashion is still lacking. We present a one-step, mask-free process to create, pattern, and tune laser-induced graphene (LIG) with a ubiquitous CO2 laser. The laser parameters are adjusted to create LIG with different electrical conductivity, surface morphology, and surface wettability without the need for postchemical modification. Such definitive control over material properties enables the creation of LIG-based integrated open microfluidics and electrochemical sensors that are capable of dividing a single water sample along four multifurcating paths to three ion selective electrodes (ISEs) for potassium (K+), nitrate (NO3-), and ammonium (NH4+) monitoring and to an enzymatic pesticide sensor for organophosphate pesticide (parathion) monitoring. The ISEs displayed near-Nernstian sensitivities and low limits of detection (LODs) (10-5.01 M, 10-5.07 M, and 10-4.89 M for the K+, NO3-, and NH4+ ISEs, respectively) while the pesticide sensor exhibited the lowest LOD (15.4 pM) for an electrochemical parathion sensor to date. LIG was also specifically patterned and tuned to create a high-performance electrochemical micro supercapacitor (MSC) capable of improving the power density by 2 orders of magnitude compared to a Li-based thin-film battery and the energy density by 3 orders of magnitude compared to a commercial electrolytic capacitor. Hence, this tunable fabrication approach to LIG is expected to enable a wide range of real-time, point-of-use health and environmental sensors as well as energy storage/harvesting modules.
ChemPhysChem, 2019
Lead halide perovskites possess unique characteristics well-suited for optoelectronic and energy ... more Lead halide perovskites possess unique characteristics well-suited for optoelectronic and energy capture devices, however, concerns about their long-term stability remain. All-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals have been reported with improved stability. We investigate the photo-and thermal-stability properties of CsPbX3 (X = Cl, Br, I) nanocrystals by electron microscopy, x-ray diffraction, thermogravimetric analysis, ensemble and single particle spectral characterization. CsPbBr¬3 is stable under 1-sun illumination for 16 h in ambient conditions, although single crystal analysis indicates the luminescence states change over time. CsPbBr¬3 is also stable to heating to 250 °C. Large CsPbI3 crystals (34 ± 5 nm) are the least stable under the same conditions; and with heating, the γ (black) phase reverts to the non-luminescent δ phase. Smaller CsPbI3 nanocrystals (14 ± 2 nm) purified by a different washing strategy exhibit improved photostability with no evidence of crystal growth but are still thermally unstable. Both CsPbCl3 and CsPbBr3 show crystal growth under irradiation or heat, likely with a preferential orientation. TGA-FTIR reveals nanocrystal mass loss was only from liberation and subsequent degradation of surface ligands. Encapsulation or other protective strategies should be employed for long-term stability under conditions of high irradiance or temperature.
New Journal of Chemistry, 2018
Nickel(ii), cobalt(ii) and manganese(ii) N-alkylimidazole bis[(trifluoromethyl)sulfonyl]imide mag... more Nickel(ii), cobalt(ii) and manganese(ii) N-alkylimidazole bis[(trifluoromethyl)sulfonyl]imide magnetic ionic liquids were synthesized from their chloride intermediates and their physicochemical properties studied.
Microchimica Acta, 2022
Current solid-contact ion-selective electrodes (ISEs) suffer from signal-to-noise drift and short... more Current solid-contact ion-selective electrodes (ISEs) suffer from signal-to-noise drift and short lifespans partly due to water uptake and the development of an aqueous layer between the transducer and ion-selective membrane. To address these challenges, we report on a nitrate ISE based on hydrophobic laser-induced graphene (LIG) coated with a poly(vinyl) chloride–based nitrate selective membrane. The hydrophobic LIG was created using a polyimide substrate and a double lasing process under ambient conditions (air at 23.0 ± 1.0 °C) that resulted in a static water contact angle of 135.5 ± 0.7° (mean ± standard deviation) in wettability testing. The LIG–ISE displayed a Nernstian response of − 58.17 ± 4.21 mV dec−1 and a limit-of-detection (LOD) of 6.01 ± 1.44 µM. Constant current chronopotentiometry and a water layer test were used to evaluate the potential (emf) signal stability with similar performance to previously published work with graphene-based ISEs. Using a portable potentiostat, the sensor displayed comparable (p > 0.05) results to a US Environmental Protection Agency (EPA)–accepted analytical method when analyzing water samples collected from two lakes in Ames, IA. The sensors were stored in surface water samples for 5 weeks and displayed nonsignificant difference in performance (LOD and sensitivity). These results, combined with a rapid and low-cost fabrication technique, make the development of hydrophobic LIG–ISEs appealing for a wide range of long-term in situ surface water quality applications.
The integration of microfluidics and electrochemical cells is at the forefront of emerging sensor... more The integration of microfluidics and electrochemical cells is at the forefront of emerging sensors and energy systems; however, a fabrication scheme that can create both the microfluidics and electrochemical cells in a scalable fashion is still lacking. We present a one-step, mask-free process to create, pattern, and tune laser-induced graphene (LIG) with a ubiquitous CO2 laser. The laser parameters are adjusted to create LIG with different electrical conductivity, surface morphology, and surface wettability without the need for postchemical modification. Such definitive control over material properties enables the creation of LIG-based integrated open microfluidics and electrochemical sensors that are capable of dividing a single water sample along four multifurcating paths to three ion selective electrodes (ISEs) for potassium (K+), nitrate (NO3-), and ammonium (NH4+) monitoring and to an enzymatic pesticide sensor for organophosphate pesticide (parathion) monitoring. The ISEs displayed near-Nernstian sensitivities and low limits of detection (LODs) (10-5.01 M, 10-5.07 M, and 10-4.89 M for the K+, NO3-, and NH4+ ISEs, respectively) while the pesticide sensor exhibited the lowest LOD (15.4 pM) for an electrochemical parathion sensor to date. LIG was also specifically patterned and tuned to create a high-performance electrochemical micro supercapacitor (MSC) capable of improving the power density by 2 orders of magnitude compared to a Li-based thin-film battery and the energy density by 3 orders of magnitude compared to a commercial electrolytic capacitor. Hence, this tunable fabrication approach to LIG is expected to enable a wide range of real-time, point-of-use health and environmental sensors as well as energy storage/harvesting modules.
ChemPhysChem, 2019
Lead halide perovskites possess unique characteristics well-suited for optoelectronic and energy ... more Lead halide perovskites possess unique characteristics well-suited for optoelectronic and energy capture devices, however, concerns about their long-term stability remain. All-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals have been reported with improved stability. We investigate the photo-and thermal-stability properties of CsPbX3 (X = Cl, Br, I) nanocrystals by electron microscopy, x-ray diffraction, thermogravimetric analysis, ensemble and single particle spectral characterization. CsPbBr¬3 is stable under 1-sun illumination for 16 h in ambient conditions, although single crystal analysis indicates the luminescence states change over time. CsPbBr¬3 is also stable to heating to 250 °C. Large CsPbI3 crystals (34 ± 5 nm) are the least stable under the same conditions; and with heating, the γ (black) phase reverts to the non-luminescent δ phase. Smaller CsPbI3 nanocrystals (14 ± 2 nm) purified by a different washing strategy exhibit improved photostability with no evidence of crystal growth but are still thermally unstable. Both CsPbCl3 and CsPbBr3 show crystal growth under irradiation or heat, likely with a preferential orientation. TGA-FTIR reveals nanocrystal mass loss was only from liberation and subsequent degradation of surface ligands. Encapsulation or other protective strategies should be employed for long-term stability under conditions of high irradiance or temperature.
New Journal of Chemistry, 2018
Nickel(ii), cobalt(ii) and manganese(ii) N-alkylimidazole bis[(trifluoromethyl)sulfonyl]imide mag... more Nickel(ii), cobalt(ii) and manganese(ii) N-alkylimidazole bis[(trifluoromethyl)sulfonyl]imide magnetic ionic liquids were synthesized from their chloride intermediates and their physicochemical properties studied.