https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37126 Wed 19 Aug 2020 12:10:45 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35548 -1 h^-1), and durability for H₂O₂ electrogeneration by the two-electron pathway of ORR.]]> Wed 04 Dec 2019 11:57:34 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46657 3), electrocatalytic nitrogen reduction reactions (NRRs) under ambient conditions using renewable energy sources (e.g. solar) have attracted significant attention; however, the design of an efficient electrocatalyst for the NRR is a challenging task and has been of central research interest. Herein, we report the synthesis of ruthenium(iii) polyethyleneimine (Ru(iii)-PEI) catalysts supported on carboxyl-modified carbon nanotubes (Ru(iii)-PEI@MWCNTs) by a self-assembly process driven by electrostatic forces at room temperature. Our newly designed Ru(iii)-PEI@MWCNTs were employed as bifunctional catalysts for the NRR and 5-hydroxymethylfurfural (HMF) oxidation. At -0.10 V vs. the reversible hydrogen electrode (RHE), our Ru(iii)-PEI@MWCNTs exhibited the high NH₃ yield rate of 188.90 μg_NH3 mg_cat.^-1 h^-1 and the faradaic efficiency (FE) of 30.93% at room temperature. Furthermore, owing to its favorable thermodynamics for HMF oxidation, the Ru(iii)-PEI@MWCNT electrode demonstrated an impressive electrocatalytic HMF oxidation at 1.24 V, 220 mV lower than that for oxygen evolution. The two-electrode electrolyzer employing Ru(iii)-PEI@MWCNTs as a bifunctional catalyst for both the cathode and the anode showed the current density of 0.50 mA cm^-2 with the cell voltage of only 1.34 V over 27 hours of stable electrolysis with a 94% FE for 2,5-furandicarboxylic acid (FDCA) production; this suggested an outstanding performance of this electrolyzer for the coupling of NRR with HMF oxidation. This study represents the first attempt at the ground demonstration of combining NH₃ production with biomass upgrading.]]> Thu 07 Dec 2023 11:10:30 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46819 2⁻), hydrogen peroxide (H₂O₂), and hydroxyl radicals (•OH) via oxygen reduction reaction (ORR), by using Bi₄NbO₈X (X = Cl, Br) single crystalline nanoplates. Significantly, the piezo-photocatalytic process leads to the highest ORR performance of the Bi₄NbO₈Br nanoplates, exhibiting •O₂⁻, H₂O₂, and •OH evolution rates of 98.7, 792, and 33.2 µmol g⁻¹ h⁻¹, respectively. The formation of a polarized electric field and band bending allows directional separation of charge carriers, promoting the catalytic activity. Furthermore, the reductive active sites are found enriched on all the facets in the piezo–photocatalytic process, also contributing to the ORR. By piezo–photodeposition of Pt to artificially plant reductive reactive sites, the Bi₄NbO₈Br plates demonstrate largely enhanced photocatalytic H2 production activity with a rate of 203.7 µmol g⁻¹ h⁻¹. The present work advances piezo–photocatalysis as a new route for ROS generation, but also discloses the potential of piezo–photocatalytic active sites enriching for H₂ evolution.]]> Thu 01 Dec 2022 10:40:44 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46850 2 photoreduction into solar fuels is promising for generating renewable energy. Herein, SrBi₂Nb₂O₉ nanosheets are prepared as high-performance photocatalysts for CO₂ reduction, highlighting superiority of ferroelectric polarization and anisotropic charge migration. Ferroelectric polarization within SrBi₂Nb₂O₉ nanosheets provides an in-built electric field, which greatly facilitates the bulk charge separation. Also, the photogenerated electrons and holes migrate separately to the NbO₆ octahedral layers and within the ab-plane in the Bi₂O₂ layers, achieving efficient anisotropic charge migration. Without co-catalyst or sacrificial agent, SrBi₂Nb₂O₉ nanosheets show outstanding CO₂ reduction activity in producing CH₄. The ferroelectric polarization is further enhanced by electric poling and annealing post-treatments. The electrically poled SrBi₂Nb₂O₉ shows a high CH₄ evolution rate of 25.91 μmol g⁻¹ h⁻¹ with an AQE of 1.96 % at 365 nm, exceeding most of state-of-the-art photocatalysts reported to date. This work paves an avenue for development of highly efficient photocatalysts and beyond by tuning the ferroelectricity and electronic structure.]]> Mon 29 Jan 2024 18:48:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45543 4 or Fe-N₄ planar configuration. The developed Ni-N₄/GHSs/Fe-N,₄ Janus material exhibits excellent bifunctional electrocatalytic performance, in which the outer Fe-N₄ clusters dominantly contribute to high activity toward the oxygen reduction reaction (ORR), while the inner Ni-N₄ clusters are responsible for excellent activity toward the oxygen evolution reaction (OER). Density functional theory calculations demonstrate the structures and reactivities of Fe-N₄ and Ni-N₄ for the ORR and OER. The Ni-N₄/GHSs/Fe-N₄ endows a rechargeable Zn–air battery with excellent energy efficiency and cycling stability as an air-cathode, outperforming that of the benchmark Pt/C+RuO₂ air-cathode. The current work paves a new avenue for precise control of single-atom sites on carbon surface for the high-performance and selective electrocatalysts.]]> Mon 29 Jan 2024 18:00:27 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46663 3−x) electrode with an ultrahigh mass loading of 15.4 mg cm⁻² on a functionalized partially exfoliated graphite substrate using a facile electrochemical method. In addition to the highly open graphene nanosheets atop, the unique layered structures of intercalated graphite sheets ensure efficient ionic transport in the entire MoO_3−x electrode. The oxygen-containing functional groups on the exfoliated graphene can bind strongly with the MoO_3−x via formation of C–O–Mo bonding, which provides a fast electron transport path from graphene to MoO_3−x and thus allows high reversible capacity and excellent rate performance. The optimized MoO_3−x electrode delivers an outstanding areal capacitance of 4.03 F cm⁻² at 3 mA cm⁻² with an excellent rate capability which is significantly higher than the values of other molybdenum oxide based electrodes reported to date. More importantly, the areal capacitance increases proportionally with the MoO_3−x mass loading, indicating that the capacitive performance is not limited by ion diffusion even at such a high mass loading. An asymmetric supercapacitor (ASC) assembled with an MoO_3−x anode delivers a maximum volumetric energy density of 2.20 mW h cm⁻³ at a volumetric power density of 3.60 mW cm⁻³, which is superior to those of the majority of the state-of-the-art supercapacitors.]]> Mon 28 Nov 2022 18:32:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46662 3N₄) has attracted much attention due to its unique properties and excellent performance in the field of sensors, which has inspired the authors to compile this review. Although there are many reviews on the synthesis and applications of g‐C₃N₄ materials, a targeted, systematic, comprehensive summary of applications in sensors and the sensing mechanisms of g‐C₃N₄‐based nanomaterials are not published. In this review, the preparation methods and synthetic conditions for preparing g‐C₃N₄ with different morphologies, such as conventional bulk g‐C₃N₄, g‐C₃N₄ nanosheets, and g‐C₃N₄ quantum dots, are introduced in detail. By reviewing recent advances in g‐C₃N₄‐based nanomaterials in ion sensors, biosensors, gas sensors, and humidity sensors, this study provides more comprehensive and in‐depth information for the further design of g‐C₃N₄‐based sensors with enhanced performance. A brief outlook of g‐C3N4‐based sensors is presented as the conclusion of this review.]]> Mon 28 Nov 2022 18:25:37 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35507 Mon 19 Aug 2019 16:30:25 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38173 2(NO₃)₂ (HPU-10) (H₂L = 2,6-bis-(5-pyridin-4-yl-1H-[1,2,4]triazol-3-yl)- pyridine), and demonstrate that this novel chemosensor has the property of ratiometric detection of Zn2+ and Cd2+. The detection limit of HPU-10 sensing Zn²⁺ and Cd²⁺ is 0.319 and 0.965 μM, respectively. The sensing mechanism can be explained by (i) the decomposition of HPU-10 and (ii) the recombination of Zn²⁺ or Cd²⁺ with ligand forming 2HL^--Zn²⁺ or 2HL^--Cd²⁺, respectively. Moreover, the fluorescent sensor HPU-10 can detect the nitroaromatic compound 2, 4-DNP via a fluorescence quenching mechanism. The detection limits obtained from linear regression curve plots of 2, 4-DNP is calculated to be 1.69 μM. In addition, the possible use of the probe coated paper for tracing the target analytes has also been presented.]]> Fri 06 Aug 2021 13:39:40 AEST ]]>