Research proposal is a brief introduction about the research you are going to do in your Bachelors, Master’s and Ph.D degrees. Where you are supposed to write about the topic or idea you will work in your Research years.
Here is the example of the Research proposal that might be helpful for you to write yours.
Ph.D Degree Research Proposal Example
Synthesis and characterization of Cellulose based semiconductor aerogel Photocatalyst for water splitting and waste water degradation.
(Purpose and Motivation)
The increasing environmental pollution and rapid energy shortages due to heavy development of
industrialization and Water contamination has become the two serious issues worldwide. Today a
major problem about water pollution is the residual dyes from different sources like
pharmaceutical industries, textile industries, paper and pulp industries, dye and its intermediate
industries, tannery and bleaching craft industries etc. These industries introduced a wide range of
toxic organic pollutants into our natural water resources. Textile waste water and other industrial
products contain organic pollutants such as formaldehyde, azo dyes, dioxins, pesticides and heavy
metals, that can cause severe risk to humans and environment [1, 2]. These mentioned organic
chemicals are designed to be resistant to microbial, thermal, and chemical degradation. Most of
these organic dyes used are carcinogenic and can cause severe health problems in humans and sea
species.
The waste water from textile and other industries is drained into the sea water the aquatic animals
either die or contain these toxic organic pollutants in their flesh. When humans eat these affected
animals, it causes cancer of lungs and other related diseases. With growing demand of environment
remediation, pollution free-technologies and alternative energy supplies have attracted extensive
research interest. In the past era, different strategies have been used to develop efficient and green
technology for the degradation of highly toxic pollutants to non-toxic species. In line with the
improvement of the living standards, it is very much needed to work on the degradation of these
organic pollutants. These organic dyes can be treated by the Advanced Oxidation Process (AOPS).
One of them is by the use of semiconductor based photocatalyst to decolorize and to fully degrade
the azo dyes [3]. First and most investigated semi-conductor TiO2 works only in UV region of light.
In spite of extensive efforts to dope TiO2 with metallic and non-metallic elements its photoresponsive activity in the visible light has remained low [4-6]. In previous literature, many reports
have been published on Cu2O, ZnO, Fe2O3, CuS, g-C3N4 nanocomposites, that work in visible
light irradiation but impose some negative factors such as catalyst recovery is not easy. Among the
novel AOPs, the heterogeneous photocatalytic oxidation process using Sulfide semiconductors is
of special interest, specifically when visible light irradiation is concerned. These semiconductor
photocatalysts are in powder form, which means another process of catalyst recovery is required
after water treatment. Therefore, considerable amount of research work is underway to improve
the photodegradation process by making variety of composite semiconductor materials on different
catalyst carrier/support materials. This way it will be easy to recover the catalyst from treated water
and the catalyst support material will add up some extra properties to the accommodated composite
photocatalyst.
My study will focus on the idea to prepare a photocatalyst cellulose based semiconductor aerogel
to degrade organic dyes and hydrogen production. Cellulose based aerogel is a new concept to
work on.. If we use it in a cellulose based aerogel then it can be easily recovered from treated
water without imposing an extra financial burden for catalyst recovery.
Objectives
Synthesis of semiconductor photocatalyst in cellulose based aerogel (CBA),
To degrade hazardous organic dyes from waste water to find a way to avoid the powder form
of the catalyst that is bit difficult to operate on industrial level.
To replace the powdered photocatalyst because it can cause damage and corrosion to the
pumps.
Cellulose Aerogel against Dyes and its compatibility with Photocatalyst
Cellulose having chemical formula (C6H10O5) n can be sourced from many types of origin such as
plants (cottons, rice husk, banana rachis, and sugarcane bagasse) [7-10]. It is cost saving renewable
source, hydrophilic, ecofriendly and have high compatibility with nanoparticle photocatalyst
materials [11]. It has abundance in hydroxyl groups and provides high surface area for
photocatalytic activity. Cellulose aerogel also creates a highly compatible environment to hold
photocatalyst nanoparticles in its 3D structure [12]. It is water insoluble and tough natural fibrous
polymer because of its complex inter and intra molecular hydrogen bonds. The intermolecular and
intramolecular hydrogen bonding allows very packed molecular arrangement which is responsible
for the formation of three-dimensional web and crystal-like structures. The elementary single
cellulose fibril is accumulated onto each other which creates the aggregation of microfibrils
cellulose chain fibers due to strong affinity of hydrogen bonds. The chain fibers of cellulose are
resulted by the aggregation of cellulose molecules to microfibrils that may create either crystalline
(higher ordered) or amorphous (less ordered) forms. Cellulose can be classified in terms of its
structure as nanofiber (CNFs), nanocrystalline cellulose/cellulose nanocrystals (NCCs)/(CNCs),
cellulose acetate, bacterial cellulose, regenerated cellulose (RCs) and cellulose hydrogel/aerogels.
All of above have shown brilliant compatibilities with photocatalyst materials [11]. Therefore, the
selection of the kind of cellulose have direct impacts on the catalysts it holds, in its structure,
forming a new cellulose/semiconductor hybrid.
In previous reports, cellulose hydrogels showed quite high adsorption capacity against methylene
blue and acid blue due to its 3D porous structure. Cellulose is also recognized as an excellent bioadsorbent candidate for the removal of organic dyestuff [13, 14].
Cellulose has an excellent hydrophilic property, because of its abundance in electron rich hydroxyl
groups on its structure that actually interacts with a photocatalyst by electrostatic interaction [12,
15, 16]. Advantage of superfine cellulose structure is that it actually provides a mechanical support
and also help to disperse inorganic nanoparticles by providing the templated surface area for proper
nucleate precipitation. Cellulose nanofiber (CNF) provides an attractive suspension for
photocatalytic particles, because of its favorable optical and mechanical properties. In degradation
process, the optical properties of cellulose-based material are extremely important for
maximization of photocatalytic reaction, irradiated by light source within the matrix. Cellulose
possess optical transmittance property that can lead to the enhancement of the electron distribution
and its transfer to the surface of the photocatalyst[15]. Recently, Xiujie et. el successfully
penetrated xylan-CuS NPs in (CNF) cellulose structure to make composite paper for NIR induced
ablation of pathogen microorganisms [17]. Morawski and co-workers successfully made
cellulose-TiO2 nanocomposite that works in UV-Vis light irradiation [18]. The band gap of the
resultant nanocomposite was 3.09 eV, causing better photocatalytic degradation efficiency. For
instance, CaCO3 decorated cellulose was also prepared by in situ precipitation of CaCO3 into the
cellulose Aerogel for removal of Congo Red dye [19]. In another study, a nanocomposite hydrogel
was formed by in situ reduction and oxidation of Ag3PO4 in the cellulose matric which helped to
degrade rhodamine B in visible light irradiation [20]. The cellulose aerogel structure has cavities
to accommodate the particles of Ag3PO4. Similarly, another study was carried out in which Cu2O
nanoparticle functionalized cellulose-based aerogel (Cu2O/CBA) (Cellulose Based Aerogel) with
three dimensional (3D) microporous structure having abundant active sites was successfully
formed to work in visible light irradiation [12].
In this study, the feasibility of Copper based composite material in cellulose aerogel was confirmed
as shown it figure 5, we can see that the deposition of Cu2O particles on inner walls of cellulose
structure.
Figure 5: Deposition of Cu2O NPs on inner walls of cellulose aerogel structure By increasing the concentration of CuSO4, the amount of Cu2O deposition was also increased.
The adsorption and photocatalytic activity of Cu2O-b-CBA successfully degraded methylene blue.
All above studies encourage the possibility to make cellulose based CuS aerogel which can
possibly work well to degrade MB. To use cellulose for CuS with H2O2, it is challenging task.
Because the decomposition of cellulose may occur in hydrogen peroxide environment. But based
on a report published elsewhere, it was confirmed that the Fenton like reactions were successfully
carried out with NanoFibril (CNF) Cellulose aerogel based catalyst in presence of H2O2 [21].
1. Research/Experimentation Approach
Synthesis of Cellulose Aerogel:
Approach 1: Cellulose nanofibril (CNF) can be synthesized from wood Kenaf core powder as
per previously reported study [22]. Kenaf core powder can be rinsed with water (Distilled) to
remove all impurities and then it can be delignified several times by bleaching it with acidchlorite to obtain holocellulose. Defibrillation of it can be carried out using high speed blender,
by addition of 0.1mM NaCl as counter ion with 0.7 wt% of holocellulose. The produced CNF
can be freeze dried if required for making its aerogel.
Approach 1: The process involves dissolution and gelation steps. An option to make (RC)
aerogel chemically is reported in past [12]. Whereas, another approach is to produce a Nano
porous aerogel using Nano fibrillated cellulose (CNF) by using freeze drying method [23].
Cellulose powder of size 20 µm (2g) can be dissolved in 7wt% of NaOH /urea 12wt% (66g)
to get cellulose solution [12]. Addition of ammonium persulfate (0.2g) to produce free
radicals was carried out for 15 minutes at room temperature. Then acrylic acid (10g),
Acrylic amide (2g) and N,N-methyelenebisacrylamide (0.6g) were added into the
solution and the it was kept in freezer for 24 hours at negative 20 degree Celsius
temperature to conduct polymerization. Then the obtained samples were washed with
ethaonal and freeze dried to get cellulose aerogel.
Formation of Semiconductor photocatalyst;
The semiconductor photocatalyst can be prepared according to the requirement and then
it is added in the prepared Aerogl in suitable conditions and Solvents.
2. Similar Work and Conclusive Statement
Recently, a successful study on nitrogen doped TiO2 on S-PS (Syndio-tactic Poly Styrene) polymer
based aerogel is reported [24], degrading non-biodegradable organic dyes in visible light
irradiation. This study demonstrates the possibility of holding the photocatalyst nanocomposite
material in aerogel cavities of synthetic polymer. Study also reveals the fact that the efficiency of
aerogel based photocatalyst was increased because of the high surface area and better optical
properties. Another approach to immobilize TiO2 in cellulose matrix (obtained from cotton linter
pulp) was used for the photocatalytic degradation of phenol under UV light irradiation [18]. This
study opened up the new possibilities for using the Cellulose based material as a nano catalyst
carrier. Similarly, cellulose was used in another successful attempt when CaCO3 was decorated on
cellulose aerogel that aided the removal of Congo red [19]. By this report, it can now be clearly
stated that cellulose aerogel finds its useful application in photocatalytic field. Furthermore,
another report on the formation of Cu2O nanoparticle functionalized cellulose based aerogel was
found [12]. Formation of Octahedral Cu2O NPs were observed that anchored onto the surface and
inner walls of cellulose matrix. The photodegradation performance of Cu2O/CBA (Cellulose Based
Aerogel) was remarkably efficient against Methylene blue (MB).
No further work has been reported yet in this field featuring cellulose as an aerogel carrier for a
photocatalyst. Material science and environmental science applications are the top two areas where
cellulose based material find their applications but total number of publications are 4% and 3%
respectively. If we try to narrow down the search term by writing “Photocatalyst and Cellulose”,
then the number of results are very inadequate. The formation of renewable, cheaper and
environmental friendly photocatalyst/cellulose hybrid on a larger scale is the current consideration
among scientific community [18-20, 25].
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