Direct solar-driven electrochemical dissociation of H2S to H2 with 12 % solar-to-hydrogen conversion efficiency in diaphragm electrolytic reactor

Abstract

Solar-driven electrochemical dissociation of hydrogen sulfide (H2S) to hydrogen and sulfur products in photovoltaic-electrochemical (PV-EC) devices becomes an effective strategy for acid gas purification and energy-saving hydrogen production. However, available H2S splitting electrochemical devices suffer from inferior energy conversion efficiency and fussy multi-step sulfur recovery problems. Herein, we propose an integrated solar-driven PV-EC system with diaphragm electrolytic reactor to solve these challenges. The optimized system integrated commercial silicon solar delivers a high solar-to-hydrogen energy conversion efficiency of up to 12 %, with approximately 99 % H2 faradaic efficiency and demonstrates at least 50 hours of stability. More importantly, the S2-/HS- can be transformed into add-valued Na2S2O3 by one-step method in Na2SO3 media, which avoids complex sulfur recovery. This work presents an alternative method of low-energy consumption for producing H2 and high-value sulfur-related chemicals by H2S splitting through a PV-EC system.