Facile Self-assembled Of Several LDH-LB Films With Chemical Gas Sensors And Photocurrent Enhancement

The basic process of molecular self-assembly is that the molecules in the system gather from disorder to order into nanoscale aggregates.Functional composites prepared using supramolecular system self-assembly technology has a wide range of application values.Layered Double Hydroxide(LDH)is a form of anionic laminar compound.It has attracted researchers' critical attention in various important fields such as catalysis,bio-sensing,drug storage-delivery agents and electrochemical energy storage.The study found that LDH powder has the disadvantages of esay leaching between layers and difficult to recycle during use.Therefore,in recent years,the assembly of LDH to prepare novel functional thin film materials has become a hot topic of research.This research combines supramolecular self-assembly technology with functionalized LDH.And the self-assembly mechanism of the interfacial LB composite films and the performance of the composite films material were explored.Firstly,a functionalized Langmuir composite film was prepared at the gas-liquid interface between the two-dimensional Mg/Al-LDH(LDH-Ise)and four dye molecules,and the diversification process and chemical gas response mechanism of the assembly process were studied.Depending on the analysis,various synergistic effects between different dye molecules and LDH in LDH-Ise/dye LB composite film promoted the aggregation of dye on LDH surface.Compared with traditional mixed cast film,the LB composite film has higher sensitivity and circularity to acid/alkali gas.At the same time,a functionalized Nickel-iron Layered Double Hydroxide(NiFe-LDH)was prepared which was assembled at the interface with Azo-benzene compounds(N-Azo and PAA-Azo)to form a Langmuir film and studied the nanostructure and ultraviolet shielding effect.Studies have found that functional LDH assembly with two Azo-benzene compounds produces a variety of behavioral aggregates.Combined with the UV spectrum,the NiFe-LDH/Azo-benzene LB composite films have excellent ultraviolet heterogeneous stability and gas sensing performance.On this basis,in order to further explore the interaction between functionalized Nickel-iron LDH and dyes,a NF-LDH/dye assembled and ordered Langmuir film with excellent properties was designed and prepared,and the morphological characteristics and photoelectric conversion behavior were studied.The experimental results showed that after the introduction of dye structure,the gas-liquid interface LB self-assembly promoted the aggregation on LDH surface.The functional photo-anode of NF-LDH/dye LB composite film was compared with the photo-anode of pure LDH and dye coated film.The former has good photocurrent enhancement performance and stability.