Ultrasound-stimulated　piezo-electrocatalysis　has　been　studied　for　a　period;　however,　the　mechanism　is　still　unclear　mainly　due　to　the　coexistence　with　other　multiple　effects　like　sonocatalysis,　which　was　usually　ignored.　In　this　work,　with　the　non-piezoelectric　H2Ti3O7　nanowires　following　the　same　experimental　process　in　piezo-electrocatalysis,　the　sonocatalytic　reduction　performance　of　CO2　is　investigated.　By　applying　vibration　under　the　excitation　of　ultrasound　with　various　frequencies　and　powers,　it　is　found　that　CO　is　the　ultimate　product　with　a　selectivity　of　100%,　and　the　optimal　CO　yield　of　8.3　mu　mol　g(-1)　h(-1)　is　achieved　with　the　addition　of　sacrificial　agents.　The　H2Ti3O7　catalysts　are　also　found　to　present　a　good　recycling　utilization　ability.　This　work　indicates　that　the　sonocatalysis　effect　may　exist　in　the　piezo-electrocatalytic　process　using　the　ultrasonic　excitation,　which　is　suggested　to　be　taken　into　consideration　when　exploring　the　mechanism　of　piezo-electrocatalysis　in　the　future.　Published　under　an　exclusive　license　by　AIP　Publishing.