In recent times, the environmental and pure water crisis
requires
many types of scientific evaluation to handle the issues caused by
different pharmaceutical drugs. The current work involves the synthesis
of ternary hybrid nanomaterials based on Ti3C2MXene–BiFeO3 (BFO)–ZnO and their applications
as photocatalysts for the disintegration of antacids. The introduction
of the two-dimensional (2D) MXene layer in the BFO–ZnO heterostructures
not only creates additional reaction hotspots but also enhances charge-transport
properties through favorable band alignments at the interface as revealed
by scanning tunneling spectroscopy. Therefore, the ternary nanocomposite
device exhibits enhanced photocurrent and improved photocatalytic
degradation performance. The degradation efficiency of the most commercially
used antacid, pantoprazole, can reach up to 92.05% and reveals good
stability and an apparent quantum yield of 1.7%. Furthermore, possible
degradation pathways of the antacids and degradation mechanisms were
proposed by identifying degraded products using high-resolution mass
spectrometry. This work realizes the objective of formulating a metal
oxide-based hybrid nano-photocatalyst supported on a 2D MXene, which
provides an efficient way to prepare low-cost and high-efficiency
heterojunctions to disintegrate pharmaceutical contaminants from real
water matrices.
Transparent, flexible, and chemically stable conducting electrodes are the most important key components for fabricating optoelectronic devices. However, in conventional bulk metal−semiconductor (MS) junctions, Fermi-level pinning is a major concern that limits the charge transport properties of the devices. In this work, we have designed MS junctions using twodimensional (2D) MXene nanosheets and Al-doped ZnO nanoparticles as a metal and an n-type semiconductor, respectively. The heterojunction was formed by layer-by-layer self-assembly on an indium tin oxide (ITO) substrate and probed by the Pt/Ir scanning tunneling microscopy (STM) tip at room temperature. By recording the tunneling current of the components that in turn yielded the density of states of the materials, we could identify their energy positions to determine the band alignments. We then proceeded to form heterojunctions and characterized their current− voltage characteristics through scanning tunneling spectroscopy. The junctions showed rectification, and the rectification ratio varied with the semiconductor doping concentrations. However, the shift of the Fermi level toward the conduction band edge of the semiconductor reduces the Schottky barrier width and consequently lowers the rectification ratio. Additionally, the MS junction with the poly-allylamine (PAH)-functionalized MXene nanosheets and the ZnO layer show a nonrectifying nature with low contact resistance at the interface. This work shows how a functionalized 2D-metal MXene and doped ZnO nanoparticle can tune the MS junction properties, used for implementing various flexible optoelectronic devices and transistor applications.
MXenes have attracted considerable attention in the field of energy storage and conversion due to their high surface area, excellent electrical conductivity, and ability to intercalate various ions. However, achieving...
We formed a core-shell heterostructure with a brownmillerite multiferroic KBiFe 2 O 5 core and a wurtzite ZnO nanoparticle shell by sol-gel technique. The KBiFe 2 O 5 behaves as a p-type semiconductor when coupled with n-type ZnO nanoparticles. The heterostructure and the individual materials were characterized by various microscopy and spectroscopy techniques. From scanning tunneling spectroscopy and correspondingly the density of states spectra, we locate the band edges to infer the nature of the individual semiconductors. The energy level diagram of the heterostructure shows the type-II band alignment at the interface, which facilitates charge separation upon illumination. In consequence, the heterostructure reveals a better degradation yield (82.5 %) of methylene blue under sunlight and photovoltaic response compared to the individual semiconductors. The ZnO nanoparticle shell plays an important role in enhancing catalytically active sites including photogenerated charge carriers to disintegrate chemical disposal from the wastewater. All oxide heterostructures thus provide a perfect combination to maximize solar light absorption, including improved charge carrier separation at the junction by appropriate core-shell interface band alignment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.