## 1 Introduction  
Perovskites represent interesting and promising materials due to advantages such as chemical stability, photostability, low production cost, modifiable energy in the band gap, high absorption properties, as well as long carrier lifetime and diffusion length, which can be used in green and sustainable environmental applications [1]. Despite the high dielectric constant and multifunctionality of perovskite materials, they possess high density, brittleness, and low dielectric strength, as well as poor processability [2]. Polymer-perovskite nanocomposites have attracted the attention of researchers as multifunctional materials for the development of flexible components/devices with many significant technological uses, in which the favorable characteristics of inorganic perovskite nanofiller and organic polymer are effectively integrated [2]. Nanosized filler polymer composites exhibit outstanding properties due to the unique characteristics of nanoparticles, such as the high surface-to-volume ratio and large interfacial area formed between the matrix and nanoparticles, with enhanced mechanical, electrical, and thermal properties. Nanocomposites that combine the advantages of polymer and filler (ceramics) can be processed more easily and are viable alternatives to plain/doped ceramic materials [3]. PVP is a water-soluble, non-toxic amorphous nonionic polymer, with high solubility in polar solvents, widely used in the synthesis of nanoparticles [4] acting as a nanoparticle dispersant, growth modifier, and surface stabilizer, preventing agglomeration of nanoparticles [5]. Due to its amphiphilic nature, PVP can affect the morphology and growth of nanoparticles by providing solubility in various solvents, discriminative surface stabilization, controlled crystal growth, playing the role of a shape control agent and facilitating the growth of specific crystal faces, while preventing the growth others [5]. Climate change, the worldwide increase in the demand for electricity, and the depletion of the natural resources from which non-renewable energy is obtained are among the major problems facing humanity. In an attempt to resolve these issues, researchers have come to advance environmentally friendly technologies that exploit renewable energy sources and provide energy carriers [6]. Hydrogen is one such energy carrier that has attracted the attention of the scientific community due to its properties, such as its carbon-free composition and very high energy density [6,7]. This gas is currently regarded as an efficient source of environmentally friendly energy that can replace the fossil fuels considered to play a significant role in global warming [8]. There is more than one available technology for generating hydrogen and not all of them are greenhouse gas free. For example, H\({}_{2}\) can be obtained via biomass and fossil fuel burning [9], but in order to avoid damaging the environment the go-to processes are electrolysis and photoelectrolysis [10]. Today, electrochemical water splitting performed by exploiting solar energy either directly or indirectly constitutes a very promising approach for the large-scale generation of hydrogen in an environmentally friendly manner [11,12]. Water electrolysis is a well-known, simple, quick, and non-polluting way of decomposing water molecules into O\({}_{2}\) and H\({}_{2}\) via two main half-reactions: the oxygen and hydrogen evolution reactions (OER and HER) unfolding at the anode and cathode, respectively. If the electricity required by this process is supplied from renewable energy sources--such as solar, wind, and tidal energy--it becomes even more environmentally friendly [13]. One of the issues facing water electrolysis that stands out is constituted by the sluggish reaction kinetics of the OER and HER. To address this problem researchers are aiming to synthesize materials with high electrocatalytic activity for at least one of the two half-reactions.