Electronic band structure adjustable NiSxSe1-x ternary catalysts show omnipotent boosting ability in photoelectrochemistry, electrocatalysis and photocatalysis

By analyzing the XRD patterns of the synthesized samples, it was found that the peak positions of the synthesized three-way catalyst on the (101), (102), and (110) planes were shifted compared with those of Ni0.96S and Ni0.85Se and were between two between. It was also reflected in SEM and HRTEM, proving that the ternary NiSxSe1-x catalyst was successfully synthesized. Compared to Ni0.96S and Ni0.85Se, the NiSxSe1-x show two advantages: 1) the addition of the third element increases the lattice internal stress, changes the local electronic state, sets up an internal electric field, ameliorates the efficiency of carrier separation and reduces internal resistance; 2) This ternary catalyst exhibits a large adjustable range of energy bands with conduction bands that can be lower or higher than Ni0.96S and Ni0.85Se which sways its catalytic activity. In the photoelectrochemistry test, NSS1 displays a high photocurrent of 4.559 mA/cm2 at 1.23 eV vs RHE which is 2.4 times that of Ni0.85Se. The NSS1 has both higher hydrogen evolution reaction (HER) (196 mV of overvoltage, 69 mV/dec of Tafel slope) and oxygen evolution reaction (OER) (393 mV of overvoltage, 25 mV/dec of Tafel slope) activity than Ni0.96S (263 mV and 75 mV/dec in HER, no OER activity) and Ni0.85Se (226 mV and 78 mV/dec in HER, 528 mV and 123 mV/dec in HER). The photocatalytic degradation of tetracycline hydrochloride affirms the degradation rate of NSS1 is 16.2 times and 1.9 times than that of Ni0.96S and Ni0.85Se, respectively. This work showcases the potential applications of ternary catalysts.