A S-scheme heterojunction of Co9S8 decorated TiO2 for enhanced photocatalytic H2 evolution

S-Scheme Co9S8 Nanoflower/Red Phosphorus Nanosheet Heterojunctions for Enhanced Photocatalytic H2 Evolution

“…Certain amounts of CoCl 2 ·6H 2 O and C 2 H 5 NS (the molar ratio of Co to S was 9:8) were dispersed into 50 mL of solvent containing N , N -dimethylformamide and ethylene glycol with a volume ratio of 1:1; after stirring for 0.5 h, the suspension was transferred to a 100 mL Teflon-lined autoclave and treated at 200 °C for 10 h. After gradually cooling down, the precipitate was centrifuged and washed by water and ethanol several times and dried at 60 °C for 12 h …”

“…The signals of RP (JCPDS 75-0577) and Co 9 S 8 (JCPDS 86-2273) can be observed in their own XRD patterns. 41,42 The XRD pattern of 0.2% Co 9 S 8 /RP only contains the characteristic peak of RP due to the low crystallinity and tiny amount of Co 9 S 8 . Three peaks at 29.84°, 31.20°, and 52.10°can be clearly observed in the XRD patterns of 5% Co 9 S 8 /RP, belonging to the (311), (222), and (440) crystal planes of Co 9 S 8 , indicating the successful construction of the Co 9 S 8 /RP heterostructure.…”

“…Xia et al synthesized Z-scheme Co 9 S 8 /CdS nanocages to accelerate the charge separation; the hollow structure, size effect of quantum dots, and abundant active sites all resulted in an enhanced photocatalytic H 2 production performance . Huang et al used Co 9 S 8 to expand the visible-light absorption range of TiO 2 , increased the active surface area, and improved the electron–hole separation efficiency; the 20 wt % Co 9 S 8 /TiO 2 exhibited a high H 2 evolution rate, which is 13.2 times that of pure TiO 2 . However, there is no work about the heterojunction between Co 9 S 8 and RP for the photocatalytic H 2 production.…”

A direct Z-scheme NiCo2O4/ZnIn2S4 heterojunction for highly efficient visible-light-driven H2 evolution

“…17 Unfortunately, ZnIn 2 S 4 also suffers from the quick recombination of charge carriers and photocorrosion, resulting in non-durable activity. 18–20 A variety of strategies have been employed to solve the above problems, such as morphology control, 21,22 element doping, 23,24 construction of heterojunctions, 25,26 etc . Gao et al prepared a NiWO 4 /ZnIn 2 S 4 p–n heterojunction using a physical solvent evaporation method with a H 2 production rate of 30.51 mmol g −1 h −1 , which is 4.42 times that of pure ZnIn 2 S 4 .…”

“…17 Unfortunately, ZnIn 2 S 4 also suffers from the quick recombination of charge carriers and photocorrosion, resulting in non-durable activity. [18][19][20] A variety of strategies have been employed to solve the above problems, such as morphology control, 21,22 element doping, 23,24 construction of heterojunctions, 25,26 28 Many investigations show that the construction of heterojunctions with an interleaved energy band arrangement is an effective strategy to achieve efficient photocatalytic reactions. [29][30][31] Z-scheme heterojunctions are extensively applied in photocatalysis because they can separate charges rapidly and maintain their strong redox ability.…”