## 1 Introduction  
Air pollution is one of the most serious problems in the world. World Health Organization (WHO, 2018) underlined that, \"almost 9 out of 10 people breathe air that contains pollutants (such as NOx, VOCs and bioaerosols) at concentrations well over the recommended levels\". Volatile organic compounds (VOCs) are emitted gasses whose concentration up to a certain point is associated with health problems. Toluene belongs in the organic pollutants category, it is used as a model air contaminant, and can be released in air, water, or soil at places that it is produced or used. If the concentration of toluene exceeds the recommended levels (20 ppm), it can affect our nervous system like headaches, dizziness or unconsciousness, cognitive impairment, and vision and hearing loss [1]. Heterogeneous photocatalysis is a promising technology for the degradation of environmental pollutants [2, 3]. Perovskite materials (ABX3) are promising candidate as efficient photocatalysts and exhibit high stability. Cations in A and B site are 12-coordinated and 6-coordinated accordingly [4] with R\({}_{\text{A}}\) > R\({}_{\text{B}}\). In addition, X is an anion, usually O, which connects to both cations. The diversity connected to the perovskite structure as far as the properties of the materials are concerned is justified if we consider that almost all the elements of the periodic table can occupy A or B site. When B site is occupied by Ti--the compounds are called metal titanates (ATiO3). Tolerance factor is an indication of the structure's formation and stability and is expressed through [PERSON]'s formula \(\mathrm{t}=((\mathrm{r_{A}}+\mathrm{r_{O}}))/\sqrt{(2(\mathrm{r_{B}}+\mathrm{r_{O}}))}\)[5; 6], with \(\mathrm{t}\) taking values from 0.71 to 1. The ideal perovskite structure is the cubic lattice (0.9 \(<\) t \(<\) 1). Mixed oxides with \(\mathrm{t}\) lower than 0.8 crystallize in ilmenite structure [7; 8], a distortion from perovskite structure where A and Ti cations occupy octahedron sites. Ilmenite structure [9] has ordered corundum structure where each octahedron \(\mathrm{AO_{6}}\) is sandwiched by two TiO\({}_{6}\) layers [10; 11]. Metal titanates (ATO\({}_{3}\), where A: Ni, Co, Zn, Mn, Mg, Fe, Ca, Ba, Sr) have been extensively studied for photooxidation applications, due to their unique physical and chemical properties. According to the literature, ATO\({}_{3}\) has been prepared by various methods such as sonochemical method [12; 13; 14; 15], precipitation method [16], sol-gel method [17; 18; 19], wet chemical method [20], auto-ignited combustion method [21], through conventional solid-state reaction route [22], and through hydrothermal method [23; 24]. However, polyol process [25; 26]--that is followed in our work--offers a low-cost and simple way of fabricating metal titanates. A key parameter of the process is the polyol used which acts both as a solvent and as a ligand thus making the redox reactions a significant part [27]. Ethylene glycol is proven to be an effective ligand with metal ions, and it favors its 1 D structure to the polymerization of the chain structure. Up to this moment, ATO\({}_{3}\) compounds have been employed for photocatalytic hydrogen production [28; 29; 30], degradation of toxic aqueous pollutants [31; 32; 33; 34; 35; 36; 37], gas sensing [38; 39], microwave applications [40], water purification [41], and photovoltaic applications [42; 43; 44]. In TiO\({}_{2}\) and TiO\({}_{2}\)-related materials the photocatalytic degradation of gaseous pollutants like toluene [45; 46; 47], nitric oxides \(\mathrm{NO_{x}}\)[48; 49; 50], and 2-propanol [51] has been studied. [PERSON] et al., synthesized Bi-BiPO\({}_{4}\) nanocomposites through in situ solvothermal reduction for NO removal [52].