Soft chemical synthesis of nanostructured materials · Soft chemical synthesis of nanostructured materials Laboratoire de Chimie de Coordination et Catalyse Université Cadi Ayyad

Pr. Mustapha AIT ALI

Soft chemical synthesis

of nanostructured

materials

Laboratoire de Chimie de Coordination et Catalyse

Université Cadi Ayyad - Faculté des Sciences-semlalia

Marrakech –Morroco

E-mail: [email protected]

1

ACRICE 2017 Setif, Algeria, 8-11 October 2017

Université Ferhat ABBAS Sétif-1, Algérie

http://www.cnrs.fr/

http://www.cnrs.fr/

2 Outline

✓ Introduction

o Nanometer and history of nanomaterial

o Applications and economic issues

✓ Chemical Approaches to nanomaterials

✓ Metallic nanoparticles and Nanostructured

metallic oxides

✓ 2D Materials:

o Silicon nanosheets (SiNSs) and silicene

o Black phosphorus and phosphorene

✓ Conclusion


3 What is Nano ?

✓ thousand times smaller than a micron.

✓ about 500,000 times finer than the thickness of

the ballpoint pen,

✓ 30,000 times finer than the thickness of a hair

✓ 100 times smaller than the DNA molecule.

The prefix « nano » :

Greek origin, means «very small».

One nanometer (nm) one billionth of a meter (10-9 meter).


4

Nanoparticle is a particle with size less than 100 nm


What is Nano ?

Don Eigler, in IBM - Almaden research center :

Succeeds to use this microscope as “forceps of atoms".

5

Richard Feynman (Nobel Prize in Physics 1965)

In December 1959, at the annual conference of the American

Physical Society:

"What would happen if we could move atoms one by one, and

assemble them as intended? "

Scanning tunneling microscope (STM) in the early 1981s:

Intuition becomes reality

A key turning point in the history of nanomaterial


6

They capture an atom, move it by moving the tip, and then release

it on the surface at the desired location.

Write the IBM logo with 35 xenon atoms

IBM – in 1985

A key turning point in the history of nanomaterial


The structural, electronic and

chemical (Properties) consequences

are due to the presence of a high

proportion of surface area

proportional to the number of atoms

on the surface, predominate in the

most widely dispersed material.

7

One of the surface statistical

consequences of the subdivision a

cube with 16 atoms on one side.

M= number of atoms on the surface

Why Nano?


8

Since nanomaterials possess unique,

beneficial chemical, physical, and

mechanical properties, they can be

used for a wide variety of applications.

These applications include, but are

not limited to, the following:

The size of the objects determines their physical, chemical

and biological properties

What areas of application and economic issues


9

Nanodevices

Size and number of transistors in an integrated circuit



Biosensors used in research and diagnostics.

10

Pharmaceutical, biotechnology and healthcare industries



11

12 Outline

✓ Introduction

o NanomApplications and economic issues

o eter and history of nanomaterial



13 Chemical Approaches to nanomaterials


Chemical reaction is a simple method to build-

up nanomaterials.

Start with atoms or molecules and build up to

nanostructures

Fabrication is much less expensive

Top-down, chemical exfoliation has emerged as a promising

wet-chemical method for production of nanomaterials (2D

nanosheets) with advantages such as:

✓ up-scalability,

✓solution processability,

✓gram-scale quantities

✓and eco-friendliness.

Zero-dimensional (0D)

nanomaterials: nanoparticles

One-dimensional (1D)

nanomaterials such as:

nanowires nanotubes

Nano-dimentional shapes and size of materials14

Two-dimensional (2D)

nanomaterials: nanosheets


At the nanoscale, the force of attraction between two particles increases to ensure

their stabilization. As a result, a barrier potential must be developed to prevent

agglomeration

So, using Chemical synthesis (bottom-up or top-down) by selection of the good solvent

and stabilizer will lead to the isolation of nanomaterials in desired size and shape. the us

of a surfactant or polymer solutions makes it possible to avoid agglomeration.

These stabilizers which prevent agglomeration act as directing agents defining the shape

of the nanomaterials towards Zero-dimensional (0D), One-dimensional (1D) or two-

dimensional nanomaterials.

15

Threes methods are widely applied to prevent agglomeration of particles:

Stabilization modes of nanomaterials

✓ electrosteric stabilization (Combination of steric and electrostatic stabilizations).

✓ electrostatic repulsion,

✓ steric exclusion,


16 Nanomaterials: Bottom-up synthesis


In recent years, several efforts were devoted to synthesize nanomaterials

with different morphologies and size using several methodologies such as:

Coprecipitation methods:

✓ hydrothermal, solvothermal,

✓ Room temperature aqueous solution,

✓ hydrolysis,

✓ reverse micelle technique…

Sol–gel method,

Electrochemical methods…

Size control by water-soluble protective agents

NaBH4

growthphase

Suitable for H2O

Chemicalreduction

17


Nanomaterial Synthesis: room temperature coprecipitation(metallic nanoparticles)

Anodic dissolution of a metalReduction of the metal salt

intermediate to the cathode

18


Nanomaterial Synthesis: Electrochemical method(metallic nanoparticles)

19 Nanomaterial Synthesis: reverse micelle technique


20

✓ The precursors are dissolved in hot solvents (eg, n-butyl alcohol)

✓ Solvent other than water may provide more gentle reaction

conditions.

✓ If the solvent is water, the process is called the hydrothermal

method.

Nanomaterial Synthesis: solvothermal (e.g. hydrothermal )


21

Ebelmann 1846

GENERAL PROCESS : TiO2, SnO2, ZrO2….

LOW TEMPERATURE

(< 100 °C)

+2 H2O

-4 ROH

SOLVENT

Cat.

AMORPHOUS

SOLID

OLIGOMERS

HOSi

OSi

OSi

OR

O O OHRO

SiO

Si

O

OH

O

O

SiO

RO

RO

HOSi

OH

Si

O

OH

OROR

POLYMERS

GELSOLID

TRANSITIONDrying

MATERIAL

SiO2

Si(OR)4

Precursor

MOLECULE

VISCOUS LIQUID

COLLOIDS (SOL)

Nanomaterial Synthesis: sol-gel method


22 Nanomaterial Synthesis: sol-gel method


23 Nanomaterial Synthesis: sol-gel method


24 Outline

✓ Introduction

o Nanometer and history of nanomaterial

o Applications and economic issues


✓ Metallic nanoparticles and Nanostructured

metallic oxides (some results)

✓ 2D Materials:



✓ Conclusion


25

TEM image DRX Size distribution (nm)

Catalysis Communications 32 (2013) 92–100

Nickel nanoparticles: Ni-CMCNa

Synthesis of metallic nanoparticles

Rhodium nanoparticles: Rh-CMCNaSize distribution

0

5

10

15

20

25

2,5 3 3,5 4 4,5 5 5,5 6 6,5 7 7,5

nm

%

Ruthenium nanoparticles: Ru-HEA16C


26 Room temperature solution-phase synthesis of CuO (Nw) an

ZnO (Nf)


27 Room temperature solution-phase synthesis of CuO (Nw) an

ZnO (Nf)


28 Selective synthesis of nanostructured Cu(OH)2, Cu2O and CuO


29 Selective synthesis of nanostructured Cu(OH)2, Cu2O and CuO


Nitro- and ceto-aromatic reduction

Treatment of Wastewater: Methylene Blue degradation

CuO(Np) Or ZnO(Np)

Terpene oxidation: Ru(Np)

Application in catalysis


31 Outline

✓ 2D Materials:



✓ Conclusion


32

There are several categories which are classified as follows:

Their extraordinarily high specific surface area makes them

promising candidates for a variety of applications in

nanotechnology.

Two-dimensional (2D) materials


2004, graphene, a one-atom-thick planar sheet of sp2-hybridized

carbon atoms, the most widely known 2D layered material..

Silicene: two-dimensional honeycomb network of silicon

atoms like graphene

▪ 1994 Prediction(Phys. Rev. B 50, 16(1994))

▪ 2007 Prediction (Phys. Rev. B 76, 75132 (2007). )

▪ 2010 First production

Phosphorene: tow dimensional material and allotrope of

phosphorus from black phosphorus

black phosphorus (BP): new member of the 2D layered material family; the most stable allotrope amongst the group also including white, red and violet phosphorus

2014 First production of phosphorene: Monolayer or few-layer black phosphorus

A key turning point in the history of Two-dimensional (2D)

materials: one-atomic thick materials33


34 Two-dimensional (2D) materials: silicene vs graphene


35 Outline

✓ Introduction

✓ Chemical Approaches to 2D Materials

o Chemical exfoliation of 2D materials

o Stabilization modes of exfoliated 2D materials

✓ Silicon nanosheets (SiNSs): Synthesis methods

✓ Liquid-phase exfoliation of calcium disilicide

✓ Recent Advances in Silicon sheets

✓ Black phosphorus Synthesis

✓ Conclusion


Si can form various stable binary Zintl compounds, with silicon as the

anionic part and some electropositive metal (alkali, alkaline earth, or

lanthanide) as the cationic part.

Calcium disilicide (CaSi2)

✓ is a Zintl silicide with 2D silicon puckered sheets ,

✓ in which the Si6 rings are interconnected and

✓ (Si)n polyanion layers are separated by planar monolayers of Ca2+.

36 Silicon nanosheets (SiNSs): Synthesis methods (cont’d)


37

CaSi2 is an ionic (Ca2+(Si-)2) material:

✓ reduction of the charge on the negatively charged silicon layers reduces the

strong electrostatic interaction between the Ca2+ and (Si2)2-layers.

Exfoliation of calcium disilicide (1)

✓ Charge reduction can be realized by doping CaSi2 with Mg, K, Na or Li


H. Nakano, et al. Angew. Chem. 2006, 118, 6451 – 6454; Angew. Chem. Int. Ed. 2006, 45, 6303 – 6306.


With Mg-doped CaSi2 in an aqueous propylamine hydrochloride solution (PA·HCl),

Nakano obtained a stable colloidal suspension of silicon sheet:

38

Hexagonal lattice, corresponding

to the (111) planar structure of

bulk silicon (0.38 nm).

However, the silicon sheets obtained by this method turned out to be

capped with oxygen atoms.


Silicon sheets

Silicon nanoparticles

39

Unreacted CaSi2


Starting from K-doped CaSi2 in an ethanolic isopropylamine hydrochloride solution

(isPA·HCl), we have prepared a stable colloidal suspension of:

✓ silicon sheet

✓ and silicon nanoparticles


M. Ait Ali et al. J. Phys.: Condens. Matter 25 (2013) 442001 (5pp).

40

Diffusion of potassium K in CaSi2 at 160 °C, leads to formation of :

✓ the phase K2xCa1-xSi2-x (A) (predominantly),

✓ the phase KSi (B) (in a small amount),

✓ Ca metal driven by the reduction of some Ca2+ by K.

According to the obtained experimental results, we have proposed that:





X-ray diffraction pattern

Characterization of Silicon nanoparticles41

a) Large scale TEM image showing Si NPs, b) zoom crystalline TEM showing highly

crystalline silicon NPs, c) ED pattern recorded on Si NPs showing a square pattern,

d) size distribution of Si NPs.


High-Resolution Transmission Electron Microscopy

Characterization of Silicon Sheets

TEM and HR-TEM measurements show :

✓ The synthesized material consists of successive silicon sheets,

✓ that are highly ordered with respect to each other.

In other words, these silicon sheets are well-ordered single-crystalline.

Figure 2: TEM Figure 3: HR-TEM

42


Characterization of Silicon Sheets (2)

Electron Diffraction

The diffraction pattern shows a hexagonal

spot arrangement:

✓ quasi-two dimensional hexagonal direct lattice, like

that of silicene, graphene and carbon nanotubes,

✓ or from a (111) oriented sheet (puckered layer) of a

bulk diamond lattice, like bulk Si.

✓ observed spots correspond to the four (100) and the

two (-110) reflections

We deduce a value of ahex equal to 0.32 nm, (ahex is the 2D hexagonal lattice constant);

whereas (111) oriented layers of a silicon diamond lattice give a value of 0.38 nm

43


Hence the silicon sheets we obtained may correspond to 2D Si lattice honeycomb, planes,

✓ with surface lattice constant ahex = 0.32 nm, and

✓ a distance between the Si atoms’ nearest neighbors of 0.2 nm.

This Si-Si distance is close to those reported for silicene

sheet (0.2, 0.22, 0.25 nm).

44 WHAT IS NEXT? (1)

Phosphorus most abundant elements with a fraction of ~0.1% of the earth crust.

In general, phosphorus has several allotropes:

✓ two most commonly seen allotropes, white and red phosphorus,

white

phosphorus

Red

phosphorus


45 WHAT IS NEXT? (2)

The two other allotropes are discovered:

violet and black phosphorus.

✓ Good energetic stability,

✓ Good thermal stability,

✓ Mechanical properties and stability,

✓ Electronic properties,

✓ Optical properties.


46

Black phosphorus (BP) is an emerging two-dimensional (2D) material with:

✓natural bandgap,

✓unique anisotropy and extraordinary physical properties.

The bandgap tunability of BP enables a wide range of ultrafast electronics and

high frequency optoelectronic applications ranging from telecommunications to

thermal imaging covering the nearly entire electromagnetic spectrum

Number of articles published in black phosphorous

from 2000–2015small 2016

Adv. Mater. 2016

Black phosphorus properties and applications


47

(1) J. Am. Chem. Soc. 1914, 38, 609–612.

(2) Anorg. Allg. Chem. 1955, 280, 119–133.

(3) Mol. Cryst. Liq. Cryst. 1982, 86, 203–211.

(4) Inorg. Chem. 2007, 46, 4028–4035. J. Solid State Chem. 2008, 181, 1707–1711.

(5 Journal of Crystal Growth 405 (2014) 6–10.

Black phosphorus Synthesis

1981: 3.8 GPa higher than 270 ºC

2007-2008: SnI4/Sn/Au, 600°C

2014: Sn/SnI4 as the only mineralization additive

Black Phosphorus

1914: 200 ºC, 1.2 GPa

1955: liquid bismuth with 30% HNO3

White Phosphorus


48 Low-cost process for the production of black phosphorus

Catalyst/ 600-750°C


49

Scanning Microscopy Electron, EDX Analysis HR-TEM

Low-cost process for the production of black phosphorus


Conclusion50

Chemical synthesis of nanomaterials is one of the important method .

So, mastering the chemical approach is a major contribution to the progress of the science

and technology of nanomaterials, fostering the invention of new up-scalable methods for

there production.

Overall, the real evolution of nanomaterials technology will depend on how effectively

we will be able to face the challenges in:

✓ production,

✓ processing,

✓ and chemical tunability.


2D-systems confined in two dimensions as Si and P nanosheets.

Their extraordinarily high specific surface area and their specific properties makes them a

promising candidates for a variety of applications in nanotechnology

We believe that the chemical approaches shall help to translate 2D

nanomaterials from the laboratory into a real, high-impact technology.

Acknowledgement:

Dr. Omar MOUNKACHI

Pr. Mohamed HAMEDOUN

Pr. Abdelillah BENYOUSSEF

Dr. Abdelfattah MAHMOUD

Dr. Frederic BOSCHINI

Pr. Mustapha AIT ALI

Pr. Abdessadek LACHGAR

Dr. Dris IHIAWAKRIM

PR. Ovidiu ERSEN

Pr. Hamid OUGHADDOU

Pr.Abdelkader KARA


52

The 6th International Meeting on SIlicene will be held at the French

Synchrotron SOLEIL, Paris, France Dec. 13-15.

Please see www.silicene.org

http://www.silicene.org/

Documents

Soft chemical synthesis of nanostructured materials · Soft chemical synthesis of nanostructured materials Laboratoire de Chimie de Coordination et Catalyse Université Cadi Ayyad