황 함량 변화가 NiZnS 복합광촉매의 태양광 물분해 효율에 미치는 영향 (Effect of Sulfur Contents in NiZnS Composite Photocatalysts on Solar Water Splitting)

서지정보

· 발행기관 : 대한금속·재료학회
· 수록지 정보 : 대한금속·재료학회지 / 61권 / 4호 / 284 ~ 290페이지
· 저자명 : 김주현, 강은선, 김정현

초록

Solar energy is attracting much attention as an eco-friendly source for future energy needs. Herein,NiZnS photocatalysts were synthesized with a hydrothermal method at various sulfur contents. The ZnSmaterial is widely used as a photocatalyst because of its high stability, low toxicity, and excellent chargeseparation characteristics. Nickel is considered a co-component in the ZnS base to improve hydrogen evolutionefficiency, because nickel sulfide has a narrow band gap. Field emission scanning electron microscopy analysiswas used to observe particle size and shape. As the sulfur ratio increased, the particle size increased, andrelatively uniform particle sizes were obtained at the 2:2 molar ratio of NiZn:S. X-ray diffractometer analysisshowed the formation of ZnO crystals at low sulfur contents in the NiZnS photocatalysts. Among the variousNiZnS compositions, the NiZn:S ratio of 2:2 resulted in the highest hydrogen production rate (1541.5 μmol/g/h) with stable reproducibility. UV-vis spectroscopy was used to analyze light absorbance, and the band gapchanged with different sulfur contents due to the oxygen vacancies in ZnO, as identified by X-rayphotoelectron spectroscope. High amounts of thiourea used to introduce the sulfur increased the particle sizesand blocked sunlight coming to NiZnS surfaces, thereby degrading photocatalytic performance. Therefore,changing the sulfur content when fabricating the NiZnS composite photocatalysts affected the crystallinestructures and band characteristics of the materials, and it finally resulted in improved light absorption,charge separation, and the hydrogen production rate of the photocatalysts.

영어초록

Solar energy is attracting much attention as an eco-friendly source for future energy needs. Herein,NiZnS photocatalysts were synthesized with a hydrothermal method at various sulfur contents. The ZnSmaterial is widely used as a photocatalyst because of its high stability, low toxicity, and excellent chargeseparation characteristics. Nickel is considered a co-component in the ZnS base to improve hydrogen evolutionefficiency, because nickel sulfide has a narrow band gap. Field emission scanning electron microscopy analysiswas used to observe particle size and shape. As the sulfur ratio increased, the particle size increased, andrelatively uniform particle sizes were obtained at the 2:2 molar ratio of NiZn:S. X-ray diffractometer analysisshowed the formation of ZnO crystals at low sulfur contents in the NiZnS photocatalysts. Among the variousNiZnS compositions, the NiZn:S ratio of 2:2 resulted in the highest hydrogen production rate (1541.5 μmol/g/h) with stable reproducibility. UV-vis spectroscopy was used to analyze light absorbance, and the band gapchanged with different sulfur contents due to the oxygen vacancies in ZnO, as identified by X-rayphotoelectron spectroscope. High amounts of thiourea used to introduce the sulfur increased the particle sizesand blocked sunlight coming to NiZnS surfaces, thereby degrading photocatalytic performance. Therefore,changing the sulfur content when fabricating the NiZnS composite photocatalysts affected the crystallinestructures and band characteristics of the materials, and it finally resulted in improved light absorption,charge separation, and the hydrogen production rate of the photocatalysts.

참고자료

· 없음