Revolutionizing water treatment: Exploring the efficacy of MoS2/BN/rGO ternary nanocomposite in organic dye treated water for OER and HER applications

Abstract

The novelty of the present work is synthesis of 2D layered molybdenum disulfide/boron nitrate/reduced graphene oxide (MoS2/BN/rGO) ternary nanocomposites for the first time through sonication assisted hydrothermal method and explore its suitability for HER/OER applications. Also the performance evaluation was carried out against normal Distilled water as well as MB dye treated water. Flower, disk and layered morphology of MoS2, BN and rGO, respectively was confirmed from field emission scanning electron microscopy (FESEM) images. Microstructural analysis was carried out using high resolution transmission electron microscopy (HRTEM) analysis. The ternary nanocomposite revealed better degradation efficiency about 98 % of degradation against methylene blue (MB) within 45 min and the recycle analysis revealed better stability for 7 cycles. For distilled water, during the oxygen evolution reaction (OER) analysis of ternary nanocomposite showed a less over potential at 0.61 V vs. RHE @ 10 mA/cm2 and Tafel slop was calculated to be 99 mV/dec. In the case of hydrogen evolution reaction (HER), over potential @ 10 mA/cm2 was about −0.044 V vs. RHE and the Tafel slop was observed to be 115 mV/dec. The photocatalytic treated waste water was examined for both HER and OER analysis where the potential at 10 mA was about −0.422 V and 1.96 V vs. RHE, for HER and OER, respectively. Further, the Tafel slop of both HER and OER was calculated to be 290 mV/dec and 121 mV/dec, respectively. The chronoamperometry analysis confirmed better stability of the ternary nanocomposite of MoS2/BN/rGO for a period of 12 h.