esp8266-01 and arduino UNO communicating over i2c

i am not able to communicate over i2c with my esp-01 as master and UNO as slave. i get special characters sent back to esp, but my esp is sending correctly... output on my esp-01 output on my UNO is

connections are esp-01 gpio-0 to uno A4 and gpio-2 to uno A5 is it because i am not using a level shifter or any mistake in my code..?

here is my esp master code

#include <Wire.h>
#define I2CAddressESPWifi 6
int x=32;

void setup()
{
  Serial.begin(115200);
  Wire.begin(0,2);//Change to Wire.begin() for non ESP.
}

void loop()
{
  Wire.beginTransmission(I2CAddressESPWifi);
  Wire.write(x);
  Wire.endTransmission();
  x++;
  delay(1);//Required. Not sure why!

  Wire.requestFrom(I2CAddressESPWifi,10);
  Serial.print("Request Return:[");
  while (Wire.available())
  {
    delay(100);
    char c = Wire.read();
    Serial.print(c);
  }
  Serial.println("]");
  delay(500);
}

and here is my Uno slave code

#include <Wire.h>
#define I2CAddressESPWifi 6

void setup()
{
  Serial.begin(115200);
  Wire.begin(I2CAddressESPWifi);
  Wire.onReceive(espWifiReceiveEvent);
  Wire.onRequest(espWifiRequestEvent);
}

void loop()
{
  delay(1);
}

void espWifiReceiveEvent(int count)
{
  Serial.print("Received[");
  while (Wire.available())
  {
    char c = Wire.read();
    Serial.print(c);
  }
  Serial.println("]");
}

void espWifiRequestEvent()
{
  String ts = getTime();
  Serial.print("Sending:[");
  Serial.print(ts.c_str());
  Serial.println("]");
  Wire.write(ts.c_str());
}

String getTime(){
  int sec = millis() / 1000;
  int min = sec / 60;
  int hr = min / 60;
  String ts = "U:";
  if (hr<10) ts+="0";
  ts += hr;
  ts +=":";
  if ((min%60)<10) ts+="0";
  ts += min % 60;
  ts +=":";
  if ((sec%60)<10) ts+="0";
  ts += sec % 60;
  return(ts);
}