Photocatalytic and Electrocatalytic Properties of Cu-Loaded ZIF-67-Derivatized Bean Sprout-Like Co-TiO2/Ti Nanostructures

ZIF-derivatized catalysts have shown high potential in catalysis. Herein, bean sprout-like Co-TiO2/Ti nanostructures were first synthesized by thermal treatment at 800 °C under Ar-flow conditions using sacrificial ZIF-67 templated on Ti sheets. It was observed that ZIF-67 on Ti sheets started to thermally decompose at around 350 °C and was converted to the cubic phase Co3O4. The head of the bean sprout structure was observed to be Co3O4, while the stem showed a crystal structure of rutile TiO2 grown from the metallic Ti support. Cu sputter-deposited Co-TiO2/Ti nanostructures were also prepared for photocatalytic and electrocatalytic CO2 reduction performances, as well as electrochemical oxygen reaction (OER). Gas chromatography results after photocatalytic CO2 reduction showed that CH3OH, CO and CH4 were produced as major products with the highest MeOH selectivity of 64% and minor C2 compounds of C2H2, C2H4 and C2H6. For electrocatalytic CO2 reduction, CO, CH4 and C2H4 were meaningfully detected, but H2 was dominantly produced. The amounts were observed to be dependent on the Cu deposition amount. Electrochemical OER performances in 0.1 M KOH electrolyte exhibited onset overpotentials of 330–430 mV (vs. RHE) and Tafel slopes of 117–134 mV/dec that were dependent on Cu-loading thickness. The present unique results provide useful information for synthesis of bean sprout-like Co-TiO2/Ti hybrid nanostructures and their applications to CO2 reduction and electrochemical water splitting in energy and environmental fields.

METODE BUDIDAYA TAUGE DALAM SMART GREEN HOUSE DENGAN SISTEM PENYIRAMAN OTOMATIS

There are many techniques to cultivate mung bean sprout, however the process requires many human involvements which can cause problems, such as forgetting to water the mung bean sprout, cutting the tail which must be cut one by one, finding the ideal location, and detecting water leakage. In this research, mung bean sprout will be grown with an automatic watering system in a Smart Green House system, which is able to monitor the mung bean sprout using technologies such as light, temperature and humidity sensors to determine the ideal place of cultivation, water level sensor to measure remaining water level in the container, and water sensor to detect water leakage from the planting medium. Arduino Mega 2560 is used as the microcontroller in this system. The sensors and components used in the system includes Light Dependent Resistor GL5506, Water Sensor Funduino, buzzer, Ultrasonic Ping HC-SR04, Humidity and Temperature Sensor DHT11, potentiometer, servo motor, relay with 12V pump, Knee and Nipple Watering System, and Fogger Head Sprayer. The system is able to cultivate mung bean sprout with length of 3-5 cm, without losing their color in the process, and can be harvested without tail.

Optimization of NPK Medium with the Addition of Mung Bean Sprout Extract for Biomass and Lipid Production of Stanieria HS-48 as a Potential Biofuel

Stanieria strain HS-48 from Ciater hot spring, Indonesia contains lipid content in the form of fatty acids that can be used as a raw material for biodiesel. Optimization of the growth medium was used to produce high contents of microalgal lipids. The growth medium in this study utilized NPK medium with the addition of variations in the concentration of mung bean sprout extract 2% and 4%. This study aimed to determine the best concentration of mung bean sprout extract in NPK medium for the highest biomass and lipid production of Stanieria HS-48. The experiments were conducted in airlift photobioreactors (APBR) for 19 days. The highest total cell density of Stanieria HS-48 in NPK medium with the addition of variations in the concentration of mung bean sprout extract 2% and 4% were 6.165 x 106 and 4.702 x 106 cell/ml. The lipid content of the biomass from Stanieria HS-48 on NPK medium with the addition of mung bean sprout extract 2% and 4% were 62.9% and 44.8%. The study showed that the NPK medium with the addition of the concentration of mung bean sprout extract 2% was a good growth medium for increasing biomass and lipid of Stanieria HS-48.