Two-dimen Atomic Laye Imensional Material Fabricated B Layer Deposition For Photocataly Ated By Catalysis

In this study,two-dimensional nanostructure fabricated by atomic layer deposition is designed to improve the catalysis performance as it allows to obtain a high surface specific area with shorter photogenerated charge transportation.Atomic layer deposition is a film deposition technique that is based on a sequential self-limiting surface reactions which able to form a conformal deposition in angstrom level.The objective of this work includes the 2D nanostructure fabrication and its application as photocatalyst with improved performance.To achieve these objectives,some of sequential studies of ALD initial growth investigation,two-dimensional nanomaterials fabrication,and application of the 2D material for photocatalysis are performed.In the study of initial ALD growth,Al₂O₃ and TiO₂ are grown onto PET surface which then the growth mechanism and the chemical composition alteration on the interfacial layer and the ALD-grown materials are investigated.In the 2D materials fabrication both types flat and complex surfaces of polymers are employed as sacrificial substrates.The methods for the substrates removal are dissolution on the solvent and calcination at high temperature.In the two-dimensional materials for photocatalysis,TiO₂ and its composite as well as Al-doped ZnO are employed as photocatalysts.The success of deposition can be influenced by presence of reactive surface groups and the substrate feature.The typical reactive groups needed for initial reaction is functional–OH groups.Evaluation on Al₂O₃ and TiO₂ grown onto PET surface shows that C=O groups also has a significant contribution on the ALD initial growth.While the substrate feature is closely related to the precursor molecules transportation.In flat substrate,the chemical exposure can be completed shortly in tens of ms,conversely for complex substrate of three-dimensionally porous structure the exposure needs a longer time which typically of hundreds ms.Photocatalytic activity of the amorphous 2D TiO₂nanomembranes is influenced by the structure.The thinner nanomembranes has a lower degree of local order and conversely the thicker nanomembranes has a higher degree of local order in which the photocatalytic performance increases by the degree of local order.It has well known that crystallinity is beneficial for photocatalysis.By calcination at high temperatures,the TiO₂ with lower degree of local order leds to be transformed into crystallized Ti O₂ with lower degree of crystallinity and conversely,the TiO₂ amorphous with higher degree of local order is able to be transformed into TiO₂ crystalline with higher degree of crystallinity.In application,photocatalytic activity increases by increasing of the degree of crystallinity.On the other hand,photocatalytic performance of the 2D TiO₂material can be improved by forming composite structure of TiO₂/ZnO.While in Al-doped ZnO for photocatalysis,the increase of Al concentration on ZnO can improve the photocatalytic performance as Al ions can be contributed to increase the transport path of charge charriers into Zn O lattice and accelerates the photogenerated electrons transfer to the surface for degradation reactions.It clearly shown the urgency of the initial growth on the ALD layer formation as the main step during the 2D nanomaterials fabrication.In the photocatalysis application the 2D nanoarchitecture material plays a crucial role to improve the photocatalytic performance.Furthermore composite structure and metal doping are also can be as improvement efforts to increase the performance.The results achieved in this work can be for scientific and engineering contributions which have potential applications in fields like water splitting,lithium ion battery,microelectronics,and catalysis.