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In this study, a novel molybdenum disulfide (MoS(2)) nano-carbon (NC) coated cathode was developed for hydrogen production in a microbial electrolysis cell (MEC), while treating simulated urine with 2–6 times dilution (conductivity 600 mg L(−1) NH(3)-N) can adversely affect the biofilm architecture and the bacterial activity at the anode of the MEC. Exoelectrogenic bacteria for this system at the anode were identified as Tissierella (Clostridia) and Bacteroidetes taxa. Maximum ammonia-nitrogen (NH(3)-N) and phosphorus (PO(4)(3−)-P) removal were 68.7 and 98.6%, respectively. This study showed that the newly fabricated MoS(2)-NC cathode can be a cost-effective alternative to the Pt cathode for renewable bioelectrochemical hydrogen production from urine.

Lithium sulfur batteries (LSB) are attracting attention as a next generation energy storage device because of their high energy density, low cost, and environmental friendliness surpassing that of lithium ion batteries (LIBs). An in-situ transmission electron microscopy experiment performed in this work revealed a fast electrochemical reaction and minimum volume changes during lithiation and delithiation for lithium polysulfide infiltrated vat black particles. Based on this observation, we developed a simple and cost-effective method for the lithium polysulfide battery to achieve high performance by employing a nanostructured vat black/carbon cloth electrode that exhibits high electrical conductivity, good mechanical properties, and a high surface area. These benefits enabled a high sulfur loading mass, captured the lithium polysulfide intermediate reaction products, and avoided structural changes. As a result, high specific discharge capacity of 1300 mAhg−1 at 0.2 C, an outstanding rate performance (846 mAhg−1 at 2 C) and an areal capacity of up to 3.352 mAhcm−2 with a sulfur loading mass of 3.8 mg were achieved. Increasing the sulfur loading mass to 7 mg (areal capacity of up to 4.24 mAhcm−2) still resulted in a desirable discharge capacity of 928 mAhg−1. This work provides a promising path towards practical lithium sulfur batteries.

Microbial fuel cells (MFCs) have recently been applied to generate electricity from oily wastewater. Although MFCs that utilize microalgae to provide a self-supporting oxygen (O(2)) supply at the cathode have been well discussed, those with microalgae at the anode as an active biomass for treating wastewater and producing electrons are still poorly studied and understood. Here, we demonstrated a bilgewater treatment using single- and double-chamber microalgal fuel cells (SMAFC and DMAFC) capable of generating energy with a novel microalgal strain (Chlorella sorokiniana) that was initially isolated from oily wastewater. Compared to previous MFC studies using green algae, relatively high voltage output (151.3–160.1 mV, 71.3–83.4 mV m(−2) of power density) was observed in the SMAFC under O(2) controlled systems (i.e., acetate addition or light/dark cycle). It was assumed that, under the O(2) depletion, alternative electron acceptors such as bicarbonate may be utilized for power generation. A DMAFC showed better power density (up to 23.9%) compared to the SMAFC due to the separated cathode chamber which fully utilizes O(2) as an electron acceptor. Both SMAFC and DMAFC removed 67.2–77.4% of soluble chemical oxygen demands (SCOD) from the synthetic bilgewater. This study demonstrates that the application of algae-based MFCs is a feasible strategy to treat oil-in-water emulsion while generating electricity.