Photocathode-assisted redox flow desalination

Desalination techniques, such as reverse osmosis, distillation, capacitive deionization, and battery desalination, require lots of electrical or thermal energy consumption. Herein, we propose a consumption-free electrochemical desalination method based on a light-driven photocathode with a Pt/CdS/Cu2ZnSnS4(CZTS)/Mo architecture. Modification of a CdS layer on CZTS can improve the desalination performance due to the formation of inner p–n junction between CdS and CZTS which enhances the separation of the photoexcited carriers without recombination. This photocathode-assisted electrodialysis desalination plays the dual functions of both energy conversion and ion removal with the blocking of ion exchange membranes. The [Fe(CN)6]3−/4− redox couples are recirculated between the anode and photo-cathode as the electrolyte while the salt streams are fed into the middle compartment. Under light illumination, this architecture produces photo-generated electrons to the redox couples with the conversion of [Fe(CN)6]3− to [Fe(CN)6]4− at the positive chamber, causing cation capture in the presence of an ion-exchange membrane. At the same time, [Fe(CN)6]4− is oxidized at the negative reservoir. The light-driven electrochemical reaction of electrolyte redox couples can result in a continuous desalination process. This work will be significant for consumption-free photoelectrochemical desalination research

Comparison of measured and calculated water film thickness of a water-lubricated elastically supported tilting pad thrust bearing

A xenon induced fluorescence technique is used to measure the water film thickness of a rubber-supported water-lubricated tilting pad thrust bearing (RWTB). Film thickness maps are obtained over a range of speeds and loads. Based on a Thermo-Elasto-Hydrodynamic lubrication model, the calculated film thickness is compared with the measured one. The measurement shows that the lubrication regime of the RWTB can be observed and it can form a convergent wedge of lubricant. The calculated results are on par with the experimental results at low speed condition (200 r·min-1). Generally, the calculated film thickness is larger and the discrepancy between them increases respecting to the speed. The RWTB is in the hydrodynamic lubrication regime when the speed is over 200 r·min-1 and the load is less than 0.25 MPa. The comparison between the measurements and calculations verifies that the fluorescence technique can be used to measure the film thickness of water-lubricated thrust bearings