Two‐Dimensional Metal Oxide and Metal Hydroxide Nanosheets: Synthesis, Controlled Assembly and Applications in Energy Conversion and Storage

Abstract

He is currently focusing on the development of high temperature lubricants from 'soft' ceramic nanoparticles such as layered metal oxides and organosilica networks.catalysis [26] and energy storage. [27] The most widely investigated classes of exfoliated oxide nanosheets are titanates, [28] niobates [29] and titanoniobates, but various other compositions are now also known, as described in more detail below. Table 1. State of the art metal oxide nanosheet compounds. Compound name Exfoliation method Energy application(s) Remarks Ti 0.87 O 2 0.52-Acid-base by TBAOH [19b,32d] Thin film supercapacitors, [49] batteries, [50] piezos, [51] photocatalysis [52] Lateral size up to 100 μm [32d] Fe 0.8 Ti 1.2 O 4 0.8-Acid-base by TBAOH [41d] Photocatalysis [53] Ni 0.4 Ti 1.6 O 4 0.8-Acid-base by TBAOH Photocatalysis [53] Ti 0.91 O 2 0.36−Acid-base by TBAOH [18,54] Photovoltaics, [55] batteries, [56] fuel cells, [57] acid catalysis, [58] photocatalysis [59] Ti 4 O 9 2-Acid-base by TBAOH [37] Batteries, [37,60] fuel cells, [61] photocatalysis [59a,62] MnO 2 0.4-Acid-base by TBAOH [35] Supercapacitors, [35,63] Photovoltaics, [64] batteries, [65] photocatalysis [59a] Mn 1-x Ru x O 2 (x = 0.05 and 0.1) Acid-base by TBAOH [42] Supercapacitors [42] RuO 2 0.2-Acid-base by TBAOH [66] Supercapacitors, [67] fuel cells [68] Ca 2 Nb 3 O 10 − Acid-base by TBAOH [69] Ca 2 Nb 3 O 10−x N y -Acid-base by TBAOH [74] Photocatalysis [74] Ca 2 Na n−3 Nb n O 3n+1 − (n = 4, 5, 6) Acid-base by TBAOH [71] Ca 2-x Sr x Nb 3 O 10 -(x = 0, 0.5, 1, 1.5, 2) Acid-base by TBAOH [75] Photocatalysis [75] Ca 2 Nb 3-x Ta x O 10 -(x = 0.3, 1, 1.5) Acid-base by TBAOH [75] Photocatalysis [75] Ca 2 Nb 3-x Rh x O 10−δ -Acid-base by TBAOH [76] Photocatalysis [76] SrNb 2 O 6 F − Acid-base by TBAOH [69] (Eu 0.56 Ta 2 O 7 ) 2-Acid-base by TBAOH [77] TaO 3 -Acid-base by TBAOH [38] Batteries, [56b] photocatalysis [78] Sr 1.5 Ta 3 O 10 2-Acid-base by TBAOH [79] CaNaTa 3 O 10 2-Acid-base by TBAOH [20] Ca 2 Ta 3 O 10-x N y -Acid-base by TBAOH [44] Photocatalysis [44] Sr 2−x Ba x Ta 3 O 10-y N z -(x = 0.0, 0.5, 1.0) Acid-base by TBAOH [80] Photocatalysis [80] SrLaTi 2 TaO 10 2-Acid-base by TBAOH [20] Ca 2 Ta 2 TiO 10 2-Acid-base by TBAOH [20] Ti (5.2-2x)/6 Mn x/2 O 2 (x = 0.1, 0.2, 0.3, 0.4) Acid-base by TBAOH [81] Ti 1−x−y Fe x Co y O 2 (0 ≤ x ≤ 0.4 and 0 ≤ y ≤ 0.2) Acid-base by TBAOH [82] Cs 4 W 11 O 36 2-Acid-base by TBAOH [83] (MWO 6 ) -(M = Nb, Ta) Acid-base by TBAOH [45] Acid catalysis, [84] photocatalysis [85] NbMoO 6 -Acid-base by TBAOH [86] Acid catalysis [86,87] W 2 O 7 2-Acid-base by TMAOH [45] Photocatalysis [88] (Ti 1.825-x Nb x O 4 ) 0.7-(x = 0-0.03) Acid-base by TBAOH [89] (Ti 1.65 Mg 0.35 O 4 ) 0.7-Acid-base by TBAOH [90] Attempt to make (Ti 1.65 Ni 0.35 O 4 ) 0.7failed [91]Nb 3 O 8 -Acid-base by TBAOH [92] Acid catalysis, [92] photocatalysis [36,93] Nb 6 O 17 4-Acid-base by TBAOH [94] and intercalation of n-propylamine [95] Photovoltaics, [96] photocatalysis [59a][73c,97] TiNbO 5 − Acid-base by TBAOH [71] Batteries, [71] photovoltaics, [71] b...

Two‐Dimensional Metal Oxide Nanomaterials for Next‐Generation Rechargeable Batteries

“…The number of different electrode materials, which govern the performance of batteries, is being continuously expanded, and has been one of the focuses of research in the field of batteries in recent years. [72][73][74][75] Many 2D metal oxide nanomaterials, such as V 2 O 5 , Cr 2 O 3 , MnO 2 , Co 3 O 4 , etc., are fabricated by a variety of synthesis Ziqi Sun received his Ph.D. degree from the Institute of Metal Research, Chinese Academy of Sciences, in 2009. [59][60][61][62][63][64][65][66][67][68][69][70] Metal oxides are a big family for the development of functional nanomaterials, owing to the fact that oxides are the lowest-free-energy states for most metals in the periodic table in the oxidative atmosphere of the Earth, and demonstrate applications ranging from insulators to semiconductors and even superconductors.…”

“…The introduction of well-designed 2D metal oxide nanomaterials into next-generation rechargeable batteries has significantly enhanced the performance of these energy-storage devices by providing higher chemically active interfaces, shortened ion-diffusion lengths, and improved in-plane carrier-/charge-transport kinetics, which have greatly promoted the development of nanotechnology and the practical application of rechargeable batteries. [72][73][74][75] Many 2D metal oxide nanomaterials, such as V 2 O 5 , Cr 2 O 3 , MnO 2 , Co 3 O 4 , etc., are fabricated by a variety of synthesis Ziqi Sun received his Ph.D. degree from the Institute of Metal Research, Chinese Academy of Sciences, in 2009. Current opportunities and future challenges for the application of 2D nano materials in energy-storage devices to achieve high energy density, high power density, stable cyclability, etc.…”

Direct Synthesis of Highly Designable Hybrid Metal Hydroxide Nanosheets by Using Tripodal Ligands as One‐Size‐Fits‐All Modifiers

“…The chemistry and physics of two‐dimensional layered materials and nanosheets have been one of the most intriguing areas in various fields . Because of the concomitance of bulk‐scale lateral size and atomic‐scale thickness, two‐dimensional nanosheets themselves have potentially ultrahigh surface areas and unique properties, such as catalytic activity, conductivity, luminescence, and magnetism . Two‐dimensional flexible nanospaces between the layers offer unique opportunities for catalysis, ion exchange, sensing, optics, energy storage, drug delivery, and so on.…”

“…Detailed structural characterization and the applicability of this method to different metallic elements have not been investigated thoroughly. Although the intercalation and exfoliation of some brucite‐type layered metal hydroxides and LDHs with layer charges have been reported, their intercalation/exfoliation abilities are still relatively poor and depend significantly on their compositions.…”

Colloids of Holey Gd2O3 Nanosheets Converted from Exfoliated Gadolinium Hydroxide Layers

“…In addition to graphene, boron nitride, and transition metal dichalcogenides (TMDs, e.g., MoS 2 and WS 2 ), colloidal suspensions of 2D metal oxides such as MoO 3 , MnO 2 , and TiO 2 , have attracted considerable attention as an ideal material for the fabrication of large‐area continuous thin films on various substrates which are desired for practical applications such as sensors, electrochemical catalysts, solar cells, and battery electrodes . Liquid‐based exfoliation of bulk layered materials is the most widely used method to produce colloidal suspensions of 2D materials .…”