## 1 Introduction  
Since its discovery in 2004, graphene has become one of the nanomaterials of great interest in the construction of devices, due to its high electronic conductivity, mechanical flexibility, and low production cost [1]. Despite the good results obtained with graphene [2, 3], the absence of energy bandgap restricts its application in some devices, such as photodetectors, mostly due to low intrinsic responsivity. This led to the development of a series of other two-dimensional materials with different characteristics, such as the hexagonal boron nitride [4], silicene [5], borophene [6], black phosphorous [7], and two-dimensional transition metal dichalcogenides (2D TMDs) [8]. The latter have been thoroughly explored in recent years for several applications [8]. Among the 2D TMDs materials, composed of a transition metal (M) and a chalcogen (X) with generalized form MX\({}_{2}\) in which M = Mo, W, Nb, Ta, Hf, Pt, and so on, and X = S, Se, Te, the MoS\({}_{2}\) nanostructures has generated great interest in the scientific community [8; 9; 10]. Featuring a metastable metallic phase (1T), which can be stabilized or converted to a stable semiconductor phase (2H) by the appropriate heat treatment [11] or use of microwave radiation [12], MoS\({}_{2}\) has unique characteristics, such as high carrier mobility, strong electron-hole confinement and variable bandgap (1.20 to 1.89 eV) [13; 14]. The bandgap of the MoS\({}_{2}\) increases with the decrease of the crystal thickness, to below 100 nm, due to the quantum confinement effect [15], and reaches 1.89 eV for a single monolayer [13]. Thus, it can cover an extent NIR (near-infrared) electromagnetic spectrum (6560 to 10,332 nm) by changing the monolayer number. Additionally, the material changes its electronic structure from an indirect bandgap, in its bulk form, to a direct bandgap in the MoS\({}_{2}\) monolayer [16], enabling optical applications. The relationship between its optical and electrical characteristics with the number of stacked layers and the control of the 1T and 2H phases turns the MoS\({}_{2}\) into a material of great interest for applications in chemical sensors [17], hydrogen evolution reaction [18], electronic devices [19], sodium-ion battery [20], and photodetectors [21; 22]. The most commonly used synthesis methods of the two-dimensional MoS\({}_{2}\) are exfoliation (liquid [23; 24] and mechanical [24]), chemical vapor deposition (CVD) [25], and hydrothermal [26]. Due to a better relationship between uniformity, the quantity of produced material and production cost, the hydrothermal method has been the most applied in the synthesis of MoS\({}_{2}\) nanostructures, usually presenting synthesis times between 20 and 24 h [27; 28]. The microwave-assisted hydrothermal method has proved to be a good alternative to the conventional hydrothermal method, offering shorter synthesis times due to \"molecular heating\", consequently lower energy consumption, enhanced reaction selectivity, and homogeneous volumetric heating [29; 30; 31]. This method also allows the direct growth of the material on a substrate, being an alternative to conventional deposition or costly transfer methods [28; 32]. Synthesis parameters, such as time and temperature, as well as the chemical processes involved in the production of the material, allow the direct growth of the MoS\({}_{2}\) nanostructures on flexible substrates [28], like cellulose-based substrates [33; 34; 35]. These advantages will have impact in the development of paper-based electronics that emerge as a future alternative to traditional electronics, seeking low-cost electronic systems and components which can be environmentally friendly [36; 37; 38]. To meet the requirements imposed on this new generation of devices, different methods of producing materials and printing technologies are employed for the production of electronic devices [36; 38; 39; 40], like solar cells [41], thin film transistors [42], light emitting devices [43], electrochromic devices [44], and photosensors [28], among others.