## 1 Introduction  
Titanium oxide (TiO\({}_{2}\)) is a semiconductor that is widely known as a photocatalyst for the photodegradation of organic pollutants. According to [PERSON] et al. [1], when TiO\({}_{2}\) is illuminated by a light with energy higher than its band gap energy, electron-hole pairs diffuse out, creating negative electrons and oxygen that combine to become O\({}_{2}\)\({}^{-}\), while the positive electric holes and water generate hydroxyl radicals. This highly active oxygen species can then oxidize organic pollutants. For over three decades, modifications on TiO\({}_{2}\) have improved two main issues. The first is to increase catalytic reaction performance where photocatalytic improvement of TiO\({}_{2}\) has been studied by many researchers. This is important in order to make the photocatalyst become active in the wide solar spectrum since the TiO\({}_{2}\) semiconductor is only active under high energy ultraviolet (UV) light [2]. Basically, there are two common types of modifications used in preparing the visible light TiO\({}_{2}\), which are the modification of bulk and the surface of TiO\({}_{2}\). Bulk modification often resulted in the narrowing of band gap energy, whereas surface modification does not change the band gap energy. However, surface modification successfully activates the photocatalyst under visible light by acceptingthe electron from the sensitizing agent. The second is a recovery process of this photocatalyst after being treated with organic pollutants where the photodegradation of organic pollutants using TiO\({}_{2}\) is basically applied under suspension mode, which provides a high surface to volume ratio [3]. However, the recovery process of this suspension of TiO\({}_{2}\) powder with treated wastewater requires filtration. Separation of this nano-sized TiO\({}_{2}\) will clog the filter membrane and eventually penetrate through the porous filter, making the recovery process less effective [4]. Immobilization of TiO\({}_{2}\) has gained great interest since it can easily separate TiO\({}_{2}\) with treated wastewater [5]. Many papers with different types of polymers in immobilized TiO\({}_{2}\) have reported these findings after the first technique was discovered by [PERSON] et al. [6]. Polymer is normally added as a binder in immobilized TiO\({}_{2}\) to improve its durability, temperature resisting ability and absorbance affinity towards pollutants [7; 8; 9], and some polymers are also able to increase TiO\({}_{2}\) photoactivity [10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25]. In most cases, prepared immobilized TiO\({}_{2}\) used solvent-based polymers, such as polythene sheets [10], thin polythene films [11], polystyrene (PS) beads [12], expanded polystyrene (EPS) beads [13], cellulose microspheres [14], fluoro polymer resins [15], polyethylene terephthalate (PET) bottles [16], polypropylene (PP) granules [17], cellulose fibers [18], polypropylene fabric (PPF) [19], polyvinyl chloride (PVC) [20], polycarbonate (PC), poly(methyl methacrylate) (PMMA) [21], polyvinyl acetate (PVAc) [22], poly(styrene)-co-poly(4-vinylpyridine) (PSP4 VP) [23], rubber latex (an elastic hydrocarbon polymer) [24], parylene and tedlar [25]. Recently, water-based polymer binders have shown a vast potential of usage in immobilized TiO\({}_{2}\) for commercialization because they are environmentally friendly and economic. Water-based polymers, such as polyvinyl alcohol (PVA), polyaniline (PANI), polyvinyl pyrolydone (PVP) and polyethylene glycol (PEG), have performed greatly in water treatment separation, which also resulted in a significant photosensitivity to the visible light region [26; 27; 28]. For instance, [PERSON] et al. [29] decorated TiO\({}_{2}\)/PVA particles through a heat treatment method and obtained high bioactivity since the Ti-O-C bond generated led the immobilized sample to become fully in contact with the organic pollutant. TiO\({}_{2}\)/PVA developed by [PERSON] et al.