Use of synergistic effects of the co-catalyst, p-n heterojunction, and porous structure for improvement of visible-light photocatalytic H2 evolution in porous Ni2O3/Mn0.2Cd0.8S/Cu3P@Cu2S

• Published in: Journal of alloys and compounds 2020-12, Vol.845, p.155569, Article 155569
• Main Authors: Zhang, Dafeng, Tang, Yunxiang, Qiu, Xiaoxue, Yin, Jie, Su, Changhua, Pu, Xipeng
• Format: Article
• Language: English
• Subjects: Catalysts; Charge transfer; Co-catalyst; Copper sulfides; Cu3P@Cu2S; Current carriers; Heterojunctions; Hydrogen evolution; Light irradiation; Mn0.2Cd0.8S; Morphology; Nanoparticles; p-n heterojunction; P-n junctions; Photocatalysis; Photocatalytic H2 evolution; Quantum efficiency; Vulcanization
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.155569

The efficient separation and transfer of photogenerated charge carriers play indispensable roles in improving the photocatalytic H2 evolution activity. Herein, we designed a Ni2O3-modified Mn0.2Cd0.8S/Cu3P@Cu2S (MCS/CPS) p-n heterojunction structure with a porous morphology for efficient and stable photocatalytic H2 evolution under visible-light irradiation. Novel porous Cu3P@Cu2S was obtained using a vulcanization method and Cu2S nanoparticles were grown uniformly in situ on the surface of Cu3P. Ni2O3 was adopted as a co-catalyst on the MCS/CPS p-n heterojunction surfaces to promote electrons transfer. Due to the synergistic effects of the co-catalyst, p-n heterojunction, and porous morphology, the as-synthesized Ni2O3/MCS/CPS composite with 9 wt% Ni2O3 and 2.5 wt% CPS exhibits an optimal photocatalytic H2 evolution rate of 9.2 mmol g−1 h−1, which is 14.4 and 2.4 times higher than those of pure MCS and 9%Ni2O3/MCS, respectively. Meanwhile, the optimal sample exhibits an apparent quantum efficiency of 33.5% at 420 nm and an excellent stability under 20 h of irradiation. Moreover, a possible mechanism for the improved photoactivity of the as-synthesized Ni2O3/MCS/CPS composite has been discussed in this paper. •Ni2O3/MCS/CPS composite shows excellent photocatalytic activity and stability.•Ni2O3 as a cocatalyst promotes the efficient charge transfer and provides active sites.•The p-n heterojunction between MCS and CPS boosts charge separation.