THE EFFECT OF ADDITION BISPHENOL-A-POLYCARBONATE FROM CD-R WASTE AS A CATALYST FOR HYDROGEN PRODUCTION

In producing hydrogen, various methods can be used, one of which is the electrolysis of water. Electrolysis is a method for breaking water molecules into oxygen and hydrogen by using an electric current. Electrolysis does not require complicated equipment and systems, so it can be said to be the easiest method of producing hydrogen. But of the various methods for producing hydrogen, the electrolysis method is not widely used because of its low efficiency. Because of this, many efforts have been made with the aim of increasing hydrogen production in the electrolysis of water. In this paper, we use Bisphenol-A-Polycarbonate (BPA) compounds obtained from unused CD-R layers. BPA has aromatic compounds that have been tested by FTIR. Aromatic compounds can generate their own magnetic field; this magnetic field is used to disrupt hydrogen bonds in water so that the electrolysis process can be more optimal. It is also known that, on the surface of BPA, it has a tendency to be positively charged by FESEM testing. The predominantly positive BPA surface works effectively to attract OH-ions. This causes a lot of H+ ions to move freely so that the solution becomes more acidic, which results in easier mobility of electric currents. With the addition of 3 grams of BPA, it can produce 46% more ppm of hydrogen than conventional.


INTRODUCTION
In 2021 there will be a world conference on climate change, namely COP26. COP26 is the 2021 United Nations (UN) Climate Change Conference. For almost three decades, the UN has brought together almost every country for global climate summits called COPs, which stands for "Conference of the Parties". Today, climate change has shifted from a peripheral issue to a global priority. Each country agreed to work together to limit global warming to below 2 degrees and aim for 1.5 degrees, to adapt to the impacts of climate change and make financial factors available to meet this goal, declared the Paris Agreement [1].
Because of the agreement, many essential sectors are required to evolve, one of which is the automotive sector. The evolution of the automotive sector, which is now still using fossil fuels that produce pollution. The solution to pollution caused by fossil fuels is to use alternative fuels that are friendly to the environment, one of these fuels is hydrogen. Hydrogen itself is an abundant resource and does not cause pollution to the environment, so it is worthy of being a renewable fuel for vehicles using a fuel cell system.
In producing hydrogen, various methods can be used, one of which is the electrolysis of water. Electrolysis is a method for breaking water molecules into oxygen and hydrogen by using an electric current. Electrolysis does not require complicated equipment and systems, so it can be said to be the easiest method of producing hydrogen. However, of the various methods for producing hydrogen, the electrolysis method is not widely used because of its low efficiency [2].
As a result, many efforts have been made to increase hydrogen production in water electrolysis. In previous research, it was explained that the addition of graphite nitride (NiOeNi/GCN) was studied as a catalyst to accelerate hydrogen production. The results show outstanding OER (Electrocatalysts for Oxygen Evolution Reaction) performance with a low potential of 188 mV at 10 mA in an acid electrolyte and excellent stability for 10,000 cycles. NiOeNi/GCN nanocomposites have been found to be effective catalysts to increase hydrogen gas production, especially at the content of aromatic aldehydes [3]. In another study, adding an external magnetic field and graphene-activated carbon algae showed that the production of hydrogen gas obtained was doubled compared to conventional electrolysis methods [4]. In two studies, it was revealed that adding materials containing aromatic compounds could increase the production of hydrogen in the electrolysis of water. In a study conducted by Purnami et al., they innovated on the addition of Algal Activated Carbon Graphene (AACG). Magnetic fields from the aromatic compound AACG can work effectively to weaken hydrogen bonds as well as covalent bonds. Weakening these bonds can aid in the process of breaking down water molecules more easily and quickly [2].
In order to obtain large hydrogen yields, an external or additional factor is used. Many things can be done to increase productivity. There are several other things that make the productivity of the electrolysis process low, namely the resistance of the material at the electrodes. The electrode that is often used in the water electrolysis process is a graphite electrode [5]. This is because the graphite electrode layer has a porous structure or material that significantly increases the diffusion of water molecules without clogging. The external factor that I use is polycarbonate as a catalyst. Polycarbonate is obtained from the bottom layer of the CD-R. I made use of the CD-R waste that had been thrown away and piled up in the trash. Until now, little action has been taken to utilize this CD-R waste, so that it can cause environmental problems in the future. If we succeed in making the best possible use of this CD-R waste, another innovation will be formed that may have a greater effect on the environment and other fields, such as technology and science.
In this study, we used a polycarbonate that is expected to break hydrogen bonds in water, so that the electrode's work in breaking hydrogen bonds and covalent bonds is not too heavy. There are two external magnets that are used and placed close to the electrolysis vessel. In polycarbonate, there is a compound called 2,2-bis-(4-hydroxyphenyl) propane or bisphenol-A-polycarbonate (BPA), which is an engineered compound that has heat resistance and is not easily decomposed [6]. A study of the molecular structure of BPA states that BPA has a polar carbonate group but is separated by an aromatic hydrocarbon group [7]. Based on this description, in this study, bisphenol-A-polycarbonate (BPA) compounds were used as catalysts for NaCl electrolyte, which contained aromatic compounds or aromatic rings that had their own magnetic fields to disrupt hydrogen bonds in water during the electrolysis process.

MATERIALS AND METHODS
Bisphenol-A-Polycarbonate (BPA) compound was obtained from the shiny layer of CD-R waste, which was separated by a mechanical method using a cutter. After the shiny layer of CD-R was peeled off, the layer was smoothed until it became a powder with a size of 400 µm. The BPA powder is shown in Figure 1.

Figure 1. Bisphenol-A-Polycarbonate Powder 400 µm
The installation of the experimental setup used in this research is shown in Figure 2. This research used a 5-volt power supply as a power source, an MQ-8 sensor as a hydrogen gas sensor, an INA 219 sensor as an electric current sensor, and an analog pH sensor, each of which was connected via an ESP32 microcontroller. To make an electrolyte solution, 500 mL of aquades with 1 mol NaCl were added to the electrolysis reactor tube. The electrode used in this research is made from graphite with dimensions ⌀7 mm x 75 mm. The electrodes were used as a cathode and anode, installed separately at a distance of 50 mm.

Figure 2. Experimental Setup
In the process of making NaCl electrolyte solution Prepare 500 ml of distilled water using a measuring container, weigh 29.25 grams of NaCl so that the molarity becomes 1 mole. Stir until the NaCl is completely dissolved. Meanwhile, for the manufacture of polycarbonate powder, prepare used CDs which can be categorized as used goods. The bottom layer is a polycarbonate chip to store data. The separation of the layers is done by removing the polycarbonate layer of the CD with the help of a cutter or other sharp object. The process of making powder is done using a blender as a tool. Wait until the CD fragments become powder. The use of polycarbonate in the form of powder itself aims to maximize the cross-sectional area of polycarbonate that hits water during the electrolysis process so that the desired reaction occurs better. The powder used is powder that has been filtered from a mesh size of 40 with a hole size of 400 micrometers.
In the primary data collection process, prepare an electrolyte solution that will be used as a test, namely an electrolyte solution of NaCl and a catalyst, namely polycarbonate powder, as much as 4 kinds of weight 0, 1, 2 and 3 grams. Data collection of hydrogen gas ppm, current, and pH can be started by pressing the power supply switch button. Wait for the electrolysis process to complete for 20 minutes or until you have received 240 data, turn off the power supply switch and discard the electrolyte solution. After the first test is complete, repeat the step of pouring the electrolyte solution with three variations of the weight of the next polycarbonate powder, namely 1, 2, and 3 grams.

Chemical Composition of Bisphenol-A-Polycarbonate Compounds
Bisphenol-A-Polycarbonate compound obtained from CD-R waste contains 76.95% carbon and 23.05% oxygen. Carbon and oxygen in that compound come from the process of forming

Surface Charge Character Analysis of Bisphenol-A-Polycarbonate Compounds
The surface characters of BPA compound were analyzed with ImageJ software. The results of the EDS SEM were covered with a ray LUT. The ray LUT is an 8-bit image byte configuration using a flame color from blue which indicates a negative charge to white which indicates the most positive charge. The surface distribution of Bisphenol-A-Polycarbonate compound is shown in Figure 4. The surface of the BPA compound is dominated by an orange to white color surface with a dominant height. This shows that the tendency of the surface of the BPA compound to have a light color means that the compound has a tendency to have a positive electric charge [11]. With a positive charge possessed by Bisphenol-A-Polycarbonate (BPA) compounds, this charge will bind to negative ions, namely OH-so that H+ ions will be more easily released freely in an electrolyte solution.

Identification Functional Groups of Bisphenol-A-Polycarbonate Compounds
The FTIR analysis of Bisphenol-A-Polycarbonate (BPA) compounds found the presence of C=C bonded aromatic compounds with changing intensity in the wave number area of 1506.08 cm-1 and CH bonding aromatic compounds with moderate intensity in the wavenumber region 885.68, 825.78, 765.88 , and 707.40 cm-1 as well as in aromatic compounds CH bonds with strong intensity at a wavenumber of 3060.65 cm-1. The wave number regions 690-900, 3010-3100 and 1500-1600 are areas that indicate the presence of aromatic compounds [8]. Aromatic compounds are part of hydrocarbon compounds that have double bonds and single bonds, causing continuous electron delocalization. This continuous delocalization of electrons gives rise to a magnetic field [9]. The result of FTIR analysis BPA compounds is shown in Figure 5.

Interaction Analysis of BPA Compounds with H2O
The results of molecular dynamics between BPA and H2O compounds showed that the kinetic energy value of the BPA and H2O compound was 395.8698 kcal/mol, while the pure H2O compound had a lower kinetic energy value of 48.72124 kcal/mol. In addition, the affinity energy value of the BPA and H2O compound was -270,815 kcal/mol, while the pure H2O compound had a higher affinity energy value of -37,759 kcal/mol. This shows that there is a large interaction fluctuation between Bisphenol-A-Polycarbonate (BPA) compounds and H2O, resulting in high kinetic energy values. This causes the outer electrons to be more easily released due to the large interaction, resulting in the lower binding energy of each atom. This is what causes the affinity energy of Bisphenol-A-Polycarbonate (BPA) with H2O to be lower [12]. The analysis of the vibrational energy of the interaction between the BPA and H2O compounds is shown in Fig. 6. From Fig. 6, it is found that the vibrational kinetic energy of the Bisphenol-A-Polycarbonate (BPA) compound with H2O has a very unstable area, which indicates that there is a greater fluctuation in the interaction between BPA and H2O compounds. so that the interaction between Bisphenol-A-Polycarbonate (BPA) and H2O compounds is able to weaken the binding energy of each atom. The addition of BPA compounds causes a large interaction that occurs between BPA compounds and H2O. This happens because graphene oxide creates a magnetic field that weakens hydrogen bonds in water. This can be seen in Figure 7, where the presence of these compounds causes the H2O molecule to rotate to uniformly face the dipole direction. As a result of the attraction with other molecules, the H and O atoms react with each other to try to escape. Figure 7. (b) shows the lines of force for the H2O molecule after interacting with Bisphenol-A-Polycarbonate compounds. It is this interaction that causes the kinetic energy between Bisphenol-A-Polycarbonate compounds and H2O to be high because the atoms have a line of attraction that becomes irregular. The existence of a line of attraction between the atoms causes the H and O atoms to react with each other and try to escape, causing the hydrogen bonds to become weak. This causes the affinity energy between Bisphenol-A-Polycarbonate compounds and H2O to decrease, resulting in hydrogen being easily released.

Hydrogen Gas Production Concentration
From the production graph in Figure 8, it can be seen that the addition of BPA greatly affects the productivity of hydrogen. With the addition of this factor, there is a significant increase in ppm compared to the conventional method. From the graph, the addition of 3 grams of BPA becomes the variable with the highest production level, followed by 2 grams, and the lowest being 1 gram.
The addition of 1 gram of BPA alone increased production in ppm by 15% over conventional. The addition of 2 grams of BPA gave an increase of 51%. The biggest increase in production occurred with the addition of 3 grams of BPA, with 62% higher hydrogen production than conventional, as shown in Figure 9.  Hydrogen production rate in terms of the average production rate (ppm), it was found that conventional electrolysis has an average production rate of 3702.80 ppm hydrogen. With the addition of BPA 1,2, and 3 grams obtained data on the average ppm production rate of 4263.65 ppm/minute, 5601.79 ppm/minute and 6024.03 ppm/minute. The description of the data can be seen in Figure 10 and Table 1 below.

Hydrogen Bond Weaken Mechanism
Water has diamagnetic properties so that it repels magnetic attraction, causing water when added to a magnetic field, to cause the water dipole to be forced to move in a uniform direction to repel the magnetic attraction [2]. As a result of forcing the uniformity of the H2O dipole direction, the hydrogen bonds will weaken, because the hydrogen bonds will become chaotic due to forced uniformity of the dipole direction. Weak hydrogen bonds will facilitate the separation of hydrogen from oxygen from water molecules. The magnetic field generated by the aromatic ring in BPA is expected to be able to disrupt the water bond. Aromatic compounds have their own electric current, which is ACID [13]. Another method used is the GIMIC method and the amount of current that arises due to delocalization of aromatic compounds is 11.4 nA. GIMIC has been used to study the aromaticity of a wide variety of compounds, including polyaromatic hydrocarbons porphyrinoids and Möbius twisted molecules [14].

The Effect of Current Electric
The measurement of electric current is carried out on the outermost layer of the electrode using a data logger using the INA 219 sensor, which is connected to the ESP microcontroller.
During the process, the electric current (A) from the electrode increases with time. This is in accordance with the theory that producing more hydrogen requires more energy.
The electrolyte solution that becomes more acidic can cause the solution's ability to conduct electric current to increase [15]. With an increase in current, the electrolysis reaction will be faster. So, in this case, it can be said that BPA functions as a catalyst. Figure 11 depicts the rate of increase in electric current at the graphite electrode. From the graph below, it can be concluded that in the presence of BPA, the more BPA contained in the solution, the greater the current will be. The increasing flow indicates that productivity has also experienced a greater increase, as shown in Figure 8.

The Effect of Electrolyte pH
From the pH graph in Figure 12, it can be seen that the decrease in pH is in line with the level of BPA content in the water. The more BPA, the lower the pH of the solution. This decrease also occurs because the BPA surface, as shown in Fig. 4, is dominated by positive charges. When BPA is sprinkled into an electrolyte solution, it will attract a lot of negatively charged OH-ions. This allows many H+ ions to freely move. The number of H+ ions is what causes the solution to be more acidic than conventional electrolysis. The attraction of OHions to BPA can be seen in the illustration in Figure 13. From the image, it can be seen that BPA has a dominantly positive charge so that it can attract OH-ions. This makes H+ ions move more freely in the electrolyte solution, causing the pH of the solution to become more acidic. This is what causes the electrolyte solution in conventional electrolysis methods to tend to move towards alkaline properties.

ACKNOWLEDGMENTS
Based on the results of the FTIR (Fourier-Transform Infrared Spectrometer) test, it is known that Bisphenol-A-Polycarbonate (BPA) contains aromatic compounds. This proves that BPA does have its own magnetic field. Then, from the FESEM (Field Emission Scanning Electron Microscope) test on BPA, there are elements of carbon (C) and oxygen (O), with carbon elements being more dominant. It is also known that BPA has a tendency to be positively charged on its surface. The predominantly positive BPA surface works effectively to attract OH-ions. This causes a lot of H+ ions to move freely, so the solution becomes more acidic. Furthermore, the magnetic field of the aromatic compounds found in BPA is able to weaken hydrogen bonds in water so that the electrolysis process can be more optimal. With the presence of BPA, the acidity level of the solution drops drastically, which causes the electrolyte solution to increase the mobility of electric current more easily.
In terms of hydrogen productivity, when compared to conventional electrolysis, the addition of 1 gram of BPA has an effectiveness of 15%. Then the effectiveness of 51% occurs with the addition of 2 grams of BPA. The greatest productivity occurred with the addition of 3 grams of BPA, resulting in an effectiveness of 63%. From these production results, it can be concluded that the addition of BPA is proven to be able to increase hydrogen productivity in water electrolysis.